NGGTF National Grid PLC (PK)

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 6-K

REPORT OF FOREIGN PRIVATE ISSUER

PURSUANT TO RULE 13a-16 OR 15d-16

UNDER THE SECURITIES EXCHANGE ACT OF 1934

For the month of January, 2024

Commission File Number: 001-14958

NATIONAL GRID plc

(Translation of registrant’s name into English)

1-3 Strand London WC2N 5EH, England

(Address of principal executive office)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F.

Form 20-F   ☒             Form 40-F   ☐

EXPLANATORY NOTE

In connection with the issuance by National Grid plc of U.S.$750,000,000 aggregate principal amount of 5.418% Notes due 2034, National Grid plc is filing the following documents solely for incorporation into the Registration Statement on Form F-3 (File No. 333-256888):

Exhibit List

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

Exhibit 1.1

UNDERWRITING AGREEMENT

National Grid plc

$750,000,000 5.418% Notes due 2034

January 8, 2024

BNP Paribas Securities Corp.

787 Seventh Avenue

New York, NY 10019

United States of America

Citigroup Global Markets Inc.

388 Greenwich Street

New York, NY 10013

United States of America

Mizuho Securities USA LLC

1271 Avenue of the Americas

New York, NY 10020

United States of America

Morgan Stanley & Co. LLC

1585 Broadway

New York, NY 10036

United States of America

As representatives of the

several underwriters listed

in Schedule 1 hereto

Ladies and Gentlemen:

National Grid plc, a public limited company incorporated under the laws of England and Wales (the “Company”), proposes to issue and sell to the several underwriters listed in Schedule 1 hereto (the “Underwriters”), for whom you are acting as representatives (the “Representatives”), $750,000,000 principal amount of its 5.418% Notes due 2034 (the “Securities”). The Securities will be issued pursuant to an Indenture, as heretofore supplemented, dated June 12, 2023 (the “Base Indenture”), as supplemented by a second supplemental indenture dated as of January 11, 2024 (the “Second Supplemental Indenture”, and together with the Base Indenture, the “Indenture”) between the Company and The Bank of New York Mellon, London Branch, as trustee and paying agent (the “Trustee”).

The Company hereby confirms its agreement with the several Underwriters concerning the purchase and sale of the Securities, as follows:

1. Registration Statement. The Company has prepared and filed with the Securities and Exchange Commission (the “Commission”) under the Securities Act of 1933, as amended, and the rules and regulations of the Commission thereunder (collectively, the “Securities Act”), a registration statement on Form F-3 (File No. 333-256888), including a prospectus (the “Base Prospectus”), relating to the debt securities to be issued from time to time by the Company. The Company has also filed, or proposes to file, with the Commission pursuant to Rule 424 under the Securities Act a prospectus supplement specifically relating to the Securities (the “Prospectus Supplement”). The registration statement, as amended at the time it became effective, including the information, if any, deemed pursuant to Rule 430A, 430B or 430C under the Securities Act to be part of the registration statement at the time of its effectiveness (“Rule 430 Information”), is referred to herein as the “Registration Statement”; and as used herein, the term “Preliminary Prospectus” means any preliminary prospectus supplement specifically relating to the Securities that is first filed pursuant to Rule 424(b), together with the Base Prospectus, and the term “Prospectus” means the Base Prospectus as supplemented by the Prospectus Supplement specifically relating to the Securities in the form first used (or made available upon request of purchasers pursuant to Rule 173 under the Securities Act) in connection with confirmation of sales of the Securities. References in this agreement (this “Agreement”) to the Registration Statement, the Base Prospectus, any Preliminary Prospectus or the Prospectus shall be deemed to refer to and include the documents incorporated by reference therein as of the effective date of the Registration Statement or the date of such Preliminary Prospectus or the Prospectus, as the case may be. The terms “supplement,” “amendment” and “amend” as used herein with respect to the Registration Statement, any Preliminary Prospectus or the Prospectus shall be deemed to refer to and include any documents filed by the Company after such date under the Securities Exchange Act of 1934, as amended, and the rules and regulations of the Commission thereunder (collectively, the “Exchange Act”) subsequent to the date of this Agreement which are deemed to be incorporated by reference therein. Capitalized terms used but not defined herein shall have the meanings given to such terms in the Registration Statement and the Prospectus.

At or prior to 3:05 PM, the time when sales of the Securities were first made (the “Time of Sale”), the Company had prepared the following information (collectively, the “Time of Sale Information”): a Preliminary Prospectus dated January 8, 2024, and each “free-writing prospectus” (as defined pursuant to Rule 405 under the Securities Act) listed on Annex A hereto.

2. Purchase and Sale of the Securities by the Underwriters.

(a) The Company agrees to issue and sell the Securities to the several Underwriters as provided in this Agreement, and each Underwriter, on the basis of the representations, warranties and agreements set forth herein and subject to the conditions set forth herein, agrees, severally and not jointly, to purchase from the Company the respective principal amount of Securities set forth opposite such Underwriter’s name in Schedule 1 hereto at a price equal to 99.600% of the principal amount thereof plus accrued interest, if any, from January 11, 2024 to the Closing Date (as defined below). The Company will not be obligated to deliver any of the Securities except upon payment for all the Securities to be purchased as provided herein.

(b) The Company understands that the Underwriters intend to make a public offering of the Securities as soon after the effectiveness of this Agreement as in the judgment of the Representatives is advisable, and initially to offer the Securities on the terms set forth in the Time of Sale Information. The Company acknowledges and agrees that the Underwriters may offer and sell Securities to or through any affiliate of an Underwriter and that any such affiliate may offer and sell Securities purchased by it to or through any Underwriter.

(c) Payment for and delivery of the Securities will be made at the offices of Davis Polk & Wardwell London LLP at 10:00 A.M., New York City time, on January 11, 2024, or at such other time or place on the same or such other date, not later than the fifth business day thereafter, as the Representatives and the Company may agree upon in writing. The time and date of such payment and delivery is referred to herein as the “Closing Date”.

(d) Payment for the Securities shall be made by wire transfer in immediately available funds to the account(s) specified by the Company to the Representatives against delivery to the nominee of The Depository Trust Company, for the account of the Underwriters, of one or more global notes representing the Securities (collectively, the “Global Note”), with any transfer taxes payable in connection with the sale of the Securities duly paid by the Company. The Global Note will be made available for inspection by the Representatives not later than 1:00 P.M., New York City time, on the business day prior to the Closing Date.

(e) The Company acknowledges and agrees that each Underwriter is acting solely in the capacity of an arm’s length contractual counterparty to the Company with respect to the offering of Securities contemplated hereby (including in connection with determining the terms of the offering) and not as a financial advisor or a fiduciary to, or an agent of, the Company or any other person. Additionally, neither the Representatives nor any other Underwriter is advising the Company or any other person as to any legal, tax, investment, accounting or regulatory matters in any jurisdiction. The Company shall consult with its own advisors concerning such

matters and shall be responsible for making its own independent investigation and appraisal of the transactions contemplated hereby, and the Underwriters shall have no responsibility or liability to the Company with respect thereto. Any review by the Representatives or any Underwriters of the Company, the transactions contemplated hereby or other matters relating to such transactions will be performed solely for the benefit of the Representatives or such Underwriters, as the case may be, and shall not be on behalf of the Company, as the case may be, or any other person.

3. Representations and Warranties of the Company. The Company represents and warrants to each Underwriter that:

(a) Preliminary Prospectus. No order preventing or suspending the use of any Preliminary Prospectus has been issued by the Commission, and each Preliminary Prospectus, at the time of filing thereof, complied in all material respects with the Securities Act and did not contain any untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading; provided that the Company makes no representation or warranty with respect to any statements or omissions made in reliance upon and in conformity with the Underwriter Supplied Information (as defined below).

(b) Registration Statement and Prospectus. The Registration Statement is an “automatic shelf registration statement” as defined under Rule 405 of the Securities Act that has been filed with the Commission not earlier than three years prior to the date hereof; and no notice of objection of the Commission to the use of such registration statement or any post-effective amendment thereto pursuant to Rule 401(g)(2) under the Securities Act has been received by the Company. No order suspending the effectiveness of the Registration Statement or the Prospectus has been issued by the Commission and no proceeding for that purpose or pursuant to Section 8A of the Securities Act against the Company or related to the offering has been initiated or threatened by the Commission; as of the applicable effective date of the Registration Statement and any amendment thereto, the Registration Statement complied and will comply in all material respects with the Securities Act and the Trust Indenture Act of 1939, as amended, and the rules and regulations of the Commission thereunder (collectively, the “Trust Indenture Act”), and did not and will not contain any untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary in order to make the statements therein not misleading; and as of the date of the Prospectus and any amendment or supplement thereto and as of the Closing Date, the Prospectus did not and will not contain any untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading; provided that the Company makes no representation or warranty with respect to (i) that part of the Registration Statement that constitutes the Statement of Eligibility and Qualification (Form T-1) of the Trustee under the Trust Indenture Act or (ii) any statements or omissions in the Registration Statement and the Prospectus and any amendment or supplement thereto made in reliance upon and in conformity with Underwriter Supplied Information.

(c) Time of Sale Information. The Time of Sale Information, at the Time of Sale did not, and at the Closing Date will not, contain any untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading; provided that the Company makes no representation or warranty with respect to any statements or omissions made in reliance upon and in conformity with Underwriter Supplied Information. No statement of material fact included in the Prospectus has been omitted from the Time of Sale Information and no statement of material fact included in the Time of Sale Information that is required to be included in the Prospectus has been omitted therefrom.

(d) Issuer Free Writing Prospectus. The Company (including its agents and representatives, other than the Underwriters in their capacity as such) has not made, used, prepared, authorized, approved or referred to and will not prepare, make, use, authorize, approve or refer to any “written communication” (as defined in Rule 405 under the Securities Act) that constitutes an offer to sell or solicitation of an offer to buy the Securities (each such communication by the Company or its agents and representatives (other than a communication referred to in clauses (i), (ii) and (iii) below) an “Issuer Free Writing Prospectus”) other than (i) any document not constituting a prospectus pursuant to Section 2(a)(10)(a) of the Securities Act or Rule 134 under the Securities Act, (ii) the Preliminary Prospectus, (iii) the Prospectus, (iv) the documents listed on Annex A hereto, including the Pricing Term Sheet substantially in the form of Annex B hereto, which constitute part of the Time of Sale Information, and (v) any electronic road show or other written communications, in each case approved in writing in advance by the Representatives. Each such Issuer Free Writing Prospectus complies in all material respects with the Securities Act, has been or will be (within the time period specified in Rule 433) filed in accordance with the Securities Act (to the extent required thereby) and, when taken together with the Preliminary Prospectus accompanying, or delivered prior to delivery of, or filed prior to the first use of such Issuer Free Writing Prospectus, at the Time of Sale, did not, and at the Closing Date will not, contain any untrue statement of a material fact or omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading; provided that the Company makes no representation or warranty with respect to any statements or omissions made in each such Issuer Free Writing Prospectus in reliance upon and in conformity with Underwriter Supplied Information.

(e) Incorporated Documents. The documents incorporated by reference in the Registration Statement, the Prospectus or the Time of Sale Information, when filed with the Commission, conformed or will conform, as the case may be, in all material respects with the requirements of the Exchange Act, and did not and will not contain any untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading.

(f) Financial Statements. The financial statements and the related notes thereto included or incorporated by reference in the Registration Statement, the Time of Sale Information and the Prospectus comply in all material respects with the applicable requirements of the Securities Act and the Exchange Act, as applicable, and present fairly in all material respects the financial position of the Company and its subsidiaries as of the dates indicated and the results of their operations and the changes in their cash flows for the periods specified; such financial statements have been prepared in conformity with applicable international financial reporting standards (“IFRS”) as adopted by the international accounting standards board (“IASB”) applied on a consistent basis throughout the periods covered thereby, and the supporting schedules included or incorporated by reference in the Registration Statement, the Prospectus and the Time of Sale Information present fairly, in all material respects, the information required to be stated therein; and the other financial information included or incorporated by reference in the Registration Statement, the Time of Sale Information and the Prospectus has been derived from the accounting records of the Company and its subsidiaries and presents fairly, in all material respects, the information shown thereby. The interactive data in eXtensible Business Reporting Language included or incorporated by reference in the Registration Statement, the Prospectus and the Time of Sale Information fairly presents the information called for in all material respects and is prepared in accordance with the Commission’s rules and guidelines applicable thereto.

(g) No Material Adverse Change. Since the date of the most recent financial statements of the Company included or incorporated by reference in each of the Registration Statement, the Time of Sale Information and the Prospectus, (i) there has not been any material adverse change in or affecting the business, financial position, results of operations or prospects of the Company and its subsidiaries taken as a whole; and (ii) neither the Company nor any of its subsidiaries has sustained any material loss or interference with its business from fire, explosion, flood or other calamity, whether or not covered by insurance, or from any labor disturbance or dispute or any action, order or decree of any court or arbitrator or governmental or regulatory authority, except in each case as otherwise disclosed in each of the Registration Statement, the Time of Sale Information and the Prospectus.

(h) Organization, Valid Existence and Good Standing. The Company and each of its principal subsidiaries have been duly organized and are validly existing and in good standing under the laws of their respective jurisdictions of organization.

(i) Due Authorization. The Company has full right, power and authority to execute and deliver this Agreement, the Securities and the Indenture (collectively, the “Transaction Documents”) and to perform its obligations hereunder and thereunder; and all action required to be taken for the due and proper authorization, execution and delivery of each of the Transaction Documents and the consummation of the transactions contemplated thereby has been duly and validly taken.

(j) The Indenture. The Base Indenture has been duly authorized, executed and delivered by the Company and has been duly qualified under the Trust Indenture Act. The Second Supplemental Indenture has been duly authorized by the Company and on the Closing Date will be duly executed and delivered by the Company. The Indenture constitutes a valid and legally binding agreement of the Company enforceable against the Company in accordance with its terms, except as enforceability may be limited by applicable bankruptcy, insolvency or similar laws affecting the enforcement of creditors’ rights generally or by equitable principles relating to enforceability (collectively, the “Enforceability Exceptions”); and on the Closing Date the Indenture will conform in all material respects to the requirements of the Trust Indenture Act.

(k) The Securities. The Securities have been duly authorized by the Company and, when duly executed, authenticated, issued and delivered as provided in the Indenture and paid for as provided herein, will be duly and validly issued and outstanding and will constitute valid and legally binding obligations of the Company enforceable against the Company in accordance with their terms, subject to the Enforceability Exceptions, and will be entitled to the benefits of the Indenture.

(l) Underwriting Agreement. This Agreement has been duly authorized, executed and delivered by the Company.

(m) No Violation or Default. Neither the Company nor any of its principal subsidiaries is (i) in violation of its memorandum and articles of association, charter, by-laws or similar organizational documents; (ii) in default, and no event has occurred that, with notice or lapse of time or both, would constitute such a default, in the due performance or observance of any term, covenant or condition contained in any indenture, mortgage, deed of trust, loan agreement or other agreement or instrument to which the Company or any of its principal subsidiaries is a party or by which the Company or any of its principal subsidiaries is bound or to which any of the property or assets of the Company or any of its principal subsidiaries is subject; or (iii) in violation of any law or statute or any judgment, order, rule or regulation of any United States or United Kingdom court or arbitrator or governmental or regulatory authority in the United States or the United Kingdom, except, in the case of clauses (ii) and (iii) above, for any such default or violation that would not, individually or in the aggregate, have a material adverse effect on the business, financial position, results of operations or prospects of the Company and its subsidiaries taken as a whole or on the performance by the Company of its obligations under this Agreement and the Securities (a “Material Adverse Effect”)

(n) No Conflicts. The execution, delivery and performance by the Company of each of the Transaction Documents, the issuance and sale of the Securities and compliance by the Company with the terms thereof and the consummation of the transactions contemplated by the Transaction Documents will not (i) conflict with or result in a breach or violation of any of the terms or provisions of, or constitute a default under, any indenture, mortgage, deed of trust, loan agreement or other agreement or instrument to which the Company or any of its principal subsidiaries is a party or by which the Company or any of its principal subsidiaries is bound or to which any of the property or assets of the Company or any of its principal subsidiaries is subject, (ii) result in any violation of the provisions of the memorandum and articles of association, by-laws or similar organizational documents of the Company or (iii) result in the violation of any law or statute or any judgment, order, rule or regulation of any court or arbitrator or governmental or regulatory authority in the United States or the United Kingdom, except, in the case of clauses (i) and (iii) above, for any such conflict, breach or violation that would not, individually or in the aggregate, have a Material Adverse Effect.

(o) No Consents Required. No consent, approval, authorization, order, registration or qualification of or with any court or arbitrator or governmental or regulatory authority in the United States or the United Kingdom is required for the execution, delivery and performance by the Company of each of the Transaction Documents, the issuance and sale of the Securities and compliance by the Company with the terms thereof and the consummation of the transactions contemplated by the Transaction Documents, except for such consents, approvals, authorizations, orders and registrations or qualifications (i) as have been obtained under the Securities Act and the Trust Indenture Act and (ii) as may be required under applicable United States state securities laws in connection with the purchase and distribution of the Securities by the Underwriters.

(p) Legal Proceedings. Except as described or provided for in the Registration Statement, the Time of Sale Information and the Prospectus, there are no legal, governmental or regulatory investigations, actions, demands, claims, suits, arbitration, inquiries or proceedings (“Actions”) pending to which the Company or any of its subsidiaries is a party or to which any property of the Company or any of its subsidiaries is the subject that, individually or in the aggregate, if determined adversely to the Company or any of its subsidiaries, would reasonably be expected to have a Material Adverse Effect; no such Actions are threatened or, to the knowledge of the Company, contemplated by any governmental or regulatory authority or threatened by others.

(q) Independent Accountants. Deloitte LLP, who have certified certain consolidated financial statements of the Company, are an independent registered public accounting firm with respect to the Company and its subsidiaries within the applicable rules and regulations adopted by the Commission and the Public Company Accounting Oversight Board (United States) and as required by the Securities Act.

(r) Investment Company Act. The Company is not and, after giving effect to the offering and sale of the Securities and the application of the proceeds thereof as described in the Registration Statement, the Time of Sale Information and the Prospectus, will not be an “investment company” or an entity “controlled” by an “investment company” within the meaning of the Investment Company Act of 1940, as amended, and the rules and regulations of the Commission thereunder.

(s) Status under the Securities Act. The Company is not an ineligible issuer and is a well-known seasoned issuer, in each case as defined under the Securities Act, in each case at the times specified in the Securities Act in connection with the offering of the Securities.

(t) Licenses and Permits. The Company and its subsidiaries possess all licenses, certificates, permits and other authorizations issued by the appropriate federal, state, local or foreign governmental or regulatory authorities that are necessary for the conduct of their respective businesses as described in the Registration Statement, the Time of Sale Information and the Prospectus, except where the failure to possess or make the same would not, individually or in the aggregate, have a Material Adverse Effect; and except as described in the Registration Statement, the Time of Sale Information and the Prospectus, neither the Company nor any of its subsidiaries has received written notice of any revocation or modification of any such license, certificate, permit or authorization or has any reason to believe that any such license, certificate, permit or authorization will not be renewed in the ordinary course, except where such revocation or modification or non-renewal would not have a Material Adverse Effect.

(u) Disclosure Controls. The Company and its subsidiaries maintain an effective system of “disclosure controls and procedures” (as defined in Rule 13a-15(e) of the Exchange Act) that complies with the requirements of the Exchange Act and that has been designed to ensure that information required to be disclosed by the Company in reports that it files or submits under the Exchange Act is recorded, processed, summarized and reported within the time periods specified in the Commission’s rules and forms, including controls and procedures designed to ensure that such information is accumulated and communicated to the Company’s management as appropriate to allow timely decisions regarding required disclosure.

(v) Accounting Controls. The Company and its subsidiaries maintain systems of “internal control over financial reporting” (as defined in Rule 13a-15(f) of the Exchange Act) that comply with the requirements of the Exchange Act and have been designed by, or under the supervision of, their respective principal executive and principal financial officers, or persons performing similar functions, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with IFRS. The Company

and its subsidiaries maintain internal accounting controls sufficient to provide reasonable assurance that (i) transactions are executed in accordance with management’s general or specific authorizations; (ii) transactions are recorded as necessary to permit preparation of financial statements in conformity with IFRS and to maintain asset accountability; (iii) access to assets is permitted only in accordance with management’s general or specific authorization; (iv) the recorded accountability for assets is compared with the existing assets at reasonable intervals and appropriate action is taken with respect to any differences; and (v) interactive data in eXtensible Business Reporting Language included or incorporated by reference in the Registration Statement, the Prospectus and the Time of Sale Information is prepared in accordance with the Commission’s rules and guidelines applicable thereto. Except as disclosed in each of the Registration Statement, the Time of Sale Information and the Prospectus, there are no material weaknesses in the Company’s internal controls.

(w) No Unlawful Payments. Neither the Company nor any of its subsidiaries, nor any director or officer of the Company or any of its subsidiaries nor, to the knowledge of the Company, any employee, agent, affiliate or other person associated with or acting on behalf of the Company or any of its subsidiaries has (i) used any corporate funds for any unlawful contribution, gift, entertainment or other unlawful expense relating to political activity; (ii) made or taken an act in furtherance of an offer, promise or authorization of any direct or indirect unlawful payment or benefit to any foreign or domestic government official or employee, including of any government-owned or controlled entity or of a public international organization, or any person acting in an official capacity for or on behalf of any of the foregoing, or any political party or party official or candidate for political office; (iii) violated or is in violation of any provision of the Foreign Corrupt Practices Act of 1977, as amended, or any applicable law or regulation implementing the Organization for Economic Co-operation and Development Convention on Combating Bribery of Foreign Public Officials in International Business Transactions, or committed an offence under the Bribery Act 2010 of the United Kingdom, or any other applicable anti-bribery or anti-corruption law; or (iv) made, offered, agreed, requested or taken an act in furtherance of any unlawful bribe or other unlawful benefit, including, without limitation, any rebate, payoff, influence payment, kickback or other unlawful or improper payment or benefit. The Company and its subsidiaries have instituted, maintain and enforce, and will continue to maintain and enforce, policies and procedures designed to promote and ensure compliance with all applicable anti-bribery and anti-corruption laws.

(x) Compliance with Anti-Money Laundering Laws. The operations of the Company and its subsidiaries are and have been conducted at all times in compliance with applicable financial recordkeeping and reporting requirements, the applicable money laundering statutes of all jurisdictions where the Company or any of its subsidiaries conducts business, the rules and regulations thereunder and any related or similar rules, regulations or guidelines, issued, administered or enforced by any governmental agency (collectively, the “Anti-Money Laundering Laws”), and no action, suit or proceeding by or before any court or governmental agency, authority or body or any arbitrator involving the Company or any of its subsidiaries with respect to the Anti-Money Laundering Laws is pending or, to the knowledge of the Company, threatened.

(y) No Conflicts with Sanctions Laws. Neither the Company nor any of its subsidiaries, directors or officers, nor, to the knowledge of the Company, any employee, agent, affiliate or other person associated with or acting on behalf of the Company or any of its subsidiaries is currently the subject or the target of any sanctions administered or enforced by the U.S. government, (including, without limitation, the Office of Foreign Assets Control of the U.S. Department of the Treasury or the U.S. Department of State and including, without limitation, the designation as a “specially designated national” or “blocked person”), the United Nations Security Council, the European Union, His Majesty’s Treasury, or other relevant sanctions authority (collectively, “Sanctions”), nor is the Company or any of its subsidiaries located, organized or resident in a country or territory that is the subject or target of Sanctions, including, without limitation, the so-called Donetsk People’s Republic, the so-called Luhansk People’s Republic, the Crimea region of Ukraine, the Kherson region of Ukraine, the Zaporizhzhia region of Ukraine, Cuba, Iran, North Korea and Syria, (each, a “Sanctioned Country”); and the Company will not directly or indirectly use the proceeds of the offering of the Securities hereunder, or lend, contribute or otherwise make available such proceeds to any subsidiary, joint venture partner or other person or entity (i) to fund or facilitate any activities of or business with any person that, at the time of such funding or facilitation, is the subject or target of Sanctions, (ii) to fund or facilitate any activities of or business in any Sanctioned Country or (iii) in any other manner that will result in a violation by any person (including any person participating in the transaction, whether as underwriter, initial purchaser, advisor, investor or otherwise) of Sanctions. For the past five years, the Company and its subsidiaries have not engaged in, and are not now engaged in any dealings or transactions with any person that at the time of the dealing or transaction is or was the subject or the target of Sanctions or with any Sanctioned Country.

(z) Cybersecurity; Data Protection. The Company and its subsidiaries’ information technology assets and equipment, computers, systems, networks, hardware, software, websites, applications, and databases (collectively, “IT Systems”) are adequate for, and operate and perform in all material respects as required in connection with the operation of the business of the Company and its subsidiaries as currently conducted, free and clear of all material bugs, errors, defects, Trojan horses, time bombs, malware and other corruptants. The Company and its subsidiaries have implemented and maintained commercially reasonable controls, policies, procedures, and safeguards to maintain and protect their material confidential information and the integrity, continuous operation, redundancy and security of all IT Systems and data (including all personal, personally identifiable, sensitive, confidential or regulated data (“Personal Data”)) used in connection with their businesses, and there have been no breaches, violations, outages or unauthorized uses of or accesses to same, except for those that have been remedied

without material cost or liability or the duty to notify any other person, nor any incidents under internal review or investigations relating to the same. The Company and its subsidiaries are presently in material compliance with all applicable laws or statutes and all judgments, orders, rules and regulations of any court or arbitrator or governmental or regulatory authority, internal policies and contractual obligations relating to the privacy and security of IT Systems and Personal Data and to the protection of such IT Systems and Personal Data from unauthorized use, access, misappropriation or modification.

(aa) Stamp Taxes. There are no stamp duty, stamp duty reserve tax or other issuance or transfer taxes or duties or other similar fees or charges required to be paid by or on behalf of the Underwriters in the United Kingdom or any political subdivision or taxing authority thereof in connection with the execution and delivery of the Transaction Documents or the offer or sale of the Securities.

(bb) No Withholding Tax. All payments to be made by the Company on or by virtue of the execution, delivery, performance or enforcement of the Transaction Documents and all interest, principal, premium, if any, additional amounts, if any, and other payments under the Transaction Documents, under the current laws and regulations of the United Kingdom (or any other jurisdiction in which the Company is resident for tax purposes), or any political subdivision thereof (each, a “Taxing Jurisdiction”), will not, while the Securities are and continue to be listed on the New York Stock Exchange and carry a right to interest, be subject to withholding, duties, levies, deductions, charges or other similar taxes under the current laws and regulations of the Taxing Jurisdiction and are otherwise payable free and clear of any other withholding, duty, levy, deduction, charge or other similar tax in the Taxing Jurisdiction and without the necessity of obtaining any governmental authorization in the Taxing Jurisdiction.

4. Further Agreements of the Company. The Company covenants and agrees with each Underwriter that:

(a) Filings with the Commission. The Company will (i) pay the registration fees for this offering within the time period required by Rule 456(b)(i) under the Securities Act prior to the Closing Date (ii) file the Prospectus in a form approved by the Underwriters with the Commission pursuant to Rule 424 under the Securities Act not later than the close of business on the second business day following the date of determination of the public offering price of the Securities or, if applicable, such earlier time as may be required by Rule 424(b) and Rule 430A, 430B or 430C under the Securities Act. The Company will file any Issuer Free Writing Prospectus (including the Pricing Term Sheet referred to in Annex B hereto) to the extent required by Rule 433 under the Securities Act; and the Company will furnish copies of the Prospectus and each Issuer Free Writing Prospectus (to the extent not previously delivered) to the Underwriters in New York City prior to 10:00 A.M., New York City time, on the business day next succeeding the date of this Agreement in such quantities as the Representatives may reasonably request.

(b) Delivery of Copies. The Company will deliver, without charge, to each Underwriter during the Prospectus Delivery Period (as defined below), as many copies of the Prospectus (including all amendments and supplements thereto and documents incorporated by reference therein) and each Issuer Free Writing Prospectus (if applicable) as the Representatives may reasonably request. As used herein, the term “Prospectus Delivery Period” means such period of time after the first date of the public offering of the Securities as in the opinion of counsel for the Underwriters a prospectus relating to the Securities is required by law to be delivered (or required to be delivered but for Rule 172 under the Securities Act) in connection with sales of the Securities by any Underwriter or dealer.

(c) Amendments or Supplements; Issuer Free Writing Prospectuses. Before preparing, using, authorizing, approving, referring to or filing any Issuer Free Writing Prospectus, and before filing any amendment or supplement to the Registration Statement or the Prospectus, the Company will furnish to the Representatives and counsel for the Underwriters a copy of the proposed Issuer Free Writing Prospectus, amendment or supplement for review and will not prepare, use, authorize, approve, refer to or file any such Issuer Free Writing Prospectus or file any such proposed amendment or supplement to which the Representatives reasonably objects unless, in the case of a filing, the Company is required by law to make such filing.

(d) Notice to the Representatives. The Company will advise the Representatives promptly, and confirm such advice in writing, (i) when any amendment to the Registration Statement has been filed or becomes effective; (ii) when any supplement to the Prospectus or any Issuer Free Writing Prospectus or any amendment to the Prospectus or any Issuer Free Writing Prospectus has been filed; (iii) of any request by the Commission for any amendment to the Registration Statement or any amendment or supplement to the Prospectus or the receipt of any comments from the Commission relating to the Registration Statement or any other request by the Commission for any additional information; (iv) of the issuance by the Commission of any order suspending the effectiveness of the Registration Statement or preventing or suspending the use of any Preliminary Prospectus or the Prospectus, any Time of Sale Information or any Issuer Free Writing Prospectus or the initiation or threatening of any proceeding for that purpose or pursuant to Section 8A of the Securities Act; (v) of the occurrence of any event within the Prospectus Delivery Period as a result of which the Prospectus, the Time of Sale Information or any Issuer Free Writing Prospectus as then amended or supplemented would include any untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary in order to make the statements therein, in the light of the circumstances existing when the Prospectus, the Time of Sale Information or any such Issuer Free Writing Prospectus is delivered to a purchaser, not misleading; (vi)

of the receipt by the Company of any notice of objection of the Commission to the use of the Registration Statement or any post-effective amendment thereto pursuant to Rule 401(g)(2) under the Securities Act; and (vii) of the receipt by the Company of any notice with respect to any suspension of the qualification of the Securities for offer and sale in any jurisdiction or the initiation or threatening of any proceeding for such purpose; and the Company will use its reasonable best efforts to prevent the issuance of any such order suspending the effectiveness of the Registration Statement, preventing or suspending the use of any Preliminary Prospectus, any of the Time of Sale Information, Issuer Free Writing Prospectus or the Prospectus or suspending any such qualification of the Securities and, if any such order is issued, will obtain as soon as possible the withdrawal thereof.

(e) Ongoing Compliance. (1) If during the Prospectus Delivery Period (i) any event shall occur or condition shall exist as a result of which the Prospectus as then amended or supplemented would include any untrue statement of a material fact or omit to state any material fact required to be stated therein or necessary in order to make the statements therein, in the light of the circumstances existing when the Prospectus is delivered to a purchaser, not misleading or (ii) it is necessary to amend or supplement the Prospectus to comply with law, the Company will immediately notify the Underwriters thereof and forthwith prepare and, subject to paragraph (c) above, file with the Commission and furnish to the Underwriters and to such dealers as the Representatives may designate, such amendments or supplements to the Prospectus as may be necessary so that the statements in the Prospectus as so amended or supplemented will not, in the light of the circumstances existing when the Prospectus is delivered to a purchaser, be misleading or so that the Prospectus will comply with law and (2) if at any time prior to the Closing Date (i) any event shall occur or condition shall exist as a result of which the Time of Sale Information as then amended or supplemented would include any untrue statement of a material fact or omit to state any material fact necessary in order to make the statements therein, in the light of the circumstances, not misleading or (ii) it is necessary to amend or supplement the Time of Sale Information to comply with law, the Company will immediately notify the Underwriters thereof and forthwith prepare and, subject to paragraph (c) above, file with the Commission (to the extent required) and furnish to the Underwriters and to such dealers as the Representatives may designate, such amendments or supplements to the Time of Sale Information as may be necessary so that the statements in the Time of Sale Information as so amended or supplemented will not, in the light of the circumstances, be misleading or so that the Time of Sale Information will comply with law.

(f) Blue Sky Compliance. The Company will qualify the Securities for offer and sale under the securities or Blue Sky laws of such jurisdictions as the Representatives shall reasonably request and will continue such qualifications in effect so long as required for distribution of the Securities; provided that the Company shall not be required to (i) qualify as a foreign corporation or other entity or as a dealer in securities in any such jurisdiction where it would not otherwise be required to so qualify, (ii) file any general consent to service of process in any such jurisdiction or (iii) subject itself to taxation in any such jurisdiction if it is not otherwise so subject.

(g) Restriction on Issuances. During the period from the date hereof through and including the Closing Date, the Company will not, without the prior written consent of the Representatives, offer, sell, contract to sell or otherwise dispose of, in the United States, any U.S. dollar-denominated debt securities issued or guaranteed by the Company and having a tenor of more than one year.

(h) Use of Proceeds. The Company will apply the net proceeds from the sale of the Securities as described in the Registration Statement, the Time of Sale Information and the Prospectus under the heading “Use of Proceeds”.

(i) No Stabilization. The Company will not take, directly or indirectly, any action designed to or that could reasonably be expected to cause or result in any stabilization in violation of applicable laws or manipulation of the price of the Securities; provided, that no representation or warranty is made with respect to the Underwriters.

(j) Filing of Exchange Act Documents. The Company will file promptly all reports and any definitive proxy or information statements required to be filed by the Company with the Commission pursuant to Section 13(a), 13(c), 14 or 15(d) of the Exchange Act during the Prospectus Delivery Period.

(k) Exchange Listing. The Company will use its reasonable best efforts to list, subject to notice of issuance, the Securities on the New York Stock Exchange (the “Exchange”).

(l) Record Retention. The Company will, pursuant to reasonable procedures developed in good faith, retain copies of each Issuer Free Writing Prospectus that is not filed with the Commission in accordance with Rule 433 under the Securities Act.

(m) Tax Indemnities. The Company agrees with each of the Underwriters to make all payments under this Agreement without withholding or deduction for or on account of any present or future taxes, duties or governmental charges whatsoever imposed by any Taxing Jurisdiction, unless the Company is compelled by law to deduct or withhold such taxes, duties or charges. In that event, the Company shall pay such additional amounts as may be necessary in order that the net amounts received after such withholding or deduction will equal the amounts that would have been received if no withholding or deduction had been made, except to the extent that such taxes, duties or charges (a) were imposed due to some connection of an Underwriter with the Taxing Jurisdiction other than the mere entering into of this Agreement or receipt of payments hereunder or (b) would not have been imposed but for the failure of such Underwriter to comply with any reasonable certification, identification or other reporting requirements concerning the nationality, residence,

identity or connection with the Taxing Jurisdiction of the Underwriter if such compliance is required or imposed by law as a precondition to an exemption from, or reduction in, such taxes, duties or other charges. The Company further agrees to indemnify and hold harmless the Underwriter against any documentary, stamp duty, stamp duty reserve tax, sales, transaction or similar issue tax, including any interest and penalties, on the creation, issue and sale of the Securities, and on the execution, delivery, performance and enforcement of this Agreement, except to the extent already paid by the Company under clause 2(d) or clause 11(a) of this Agreement.

5. Certain Agreements of the Underwriters. Each Underwriter, severally and not jointly, hereby represents and agrees that:

(a) It has not and will not use, authorize use of, refer to, or participate in the planning for use of, any “free writing prospectus”, as defined in Rule 405 under the Securities Act (which term includes use of any written information furnished to the Commission by the Company and not incorporated by reference into the Registration Statement and any press release issued by the Company) other than (i) a free writing prospectus that, solely as a result of use by such Underwriter, would not trigger an obligation to file such free writing prospectus with the Commission pursuant to Rule 433, (ii) any Issuer Free Writing Prospectus listed on Annex A or prepared pursuant to Section 3(c) or Section 4(c) above (including any electronic road show), or (iii) any free writing prospectus prepared by such Underwriter and approved by the Company in advance in writing (each such free writing prospectus referred to in clauses (i) or (iii), an “Underwriter Free Writing Prospectus”). Notwithstanding the foregoing, the Underwriters may use the Pricing Term Sheet referred to in Annex B hereto without the consent of the Company.

(b) Other than in the United States, no action has been or will be taken by the Company in any jurisdiction that would permit a public offering of the Securities or possession or distribution of any Issuer Free Writing Prospectus, any Underwriter Free Writing Prospectus, the Time of Sale Information or the Prospectus or any amendment or supplement thereto or any other offering material relating to the Securities in any country or jurisdiction where action for that purpose is required.

(c) It is not subject to any pending proceeding under Section 8A of the Securities Act with respect to the offering (and will promptly notify the Company if any such proceeding against it is initiated during the Prospectus Delivery Period).

(d) Financial Promotion. It has only communicated or caused to be communicated and will only communicate or cause to be communicated any invitation or inducement to engage in investment activity (within the meaning of section 21 of the Financial Services and Markets Act 2000 (the “FSMA”) of Great Britain) received by it in connection with the issue or sale of such Securities or any investments representing the Securities (including without limitation the Registration Statement registering the Securities, the Time of Sale Information and the Prospectus) in circumstances in which section 21(1) of the FSMA does not apply to the Company.

(e) General Compliance. (1) It has complied and will comply with all the applicable provisions of the FSMA with respect to anything done by it in relation to any Securities in, from or otherwise involving the United Kingdom.

(2) It has not offered, sold or otherwise made available and will not offer, sell or otherwise make available any Securities to any retail investor in the United Kingdom. For the purposes of this provision:

(A) the expression “retail investor” means a person who is one (or more) of the following:

(i) a retail client, as defined in point (8) of Article 2 of Regulation (EU) No 2017/565 as it forms part of domestic law by virtue of the European Union (Withdrawal) Act 2018, as amended (“EUWA”); or

(ii) a customer within the meaning of the provisions of the FSMA and any rules or regulations made under the FSMA to implement Directive (EU) 2016/97, where that customer would not qualify as a professional client, as defined in point (8) of Article 2(1) of Regulation (EU) No 600/2014 as it forms part of domestic law by virtue of the EUWA; or

(iii) not a qualified investor as defined in Article 2 of Regulation (EU) 2017/1129 as it forms part of domestic law by virtue of the EUWA ; and

(B) the expression “offer” includes the communication in any form and by any means of sufficient information on the terms of the offer and the Notes to be offered so as to enable an investor to decide to purchase or subscribe for the Securities.

(3) It has not offered, sold or otherwise made available and will not offer, sell or otherwise make available any Securities to any retail investor in the European Economic Area. For the purposes of this provision:

(A) the expression “retail investor” means a person who is one (or more) of the following:

(i) a retail client as defined in point (11) of Article 4(1) of Directive 2014/65/EU (as amended, “MiFID II”); or

(ii) a customer within the meaning of Directive (EU) 2016/97 (the “Insurance Distribution Directive”), where that customer would not qualify as a professional client as defined in point (10) of Article 4(1) of MiFID II; or

(iii) not a qualified investor as defined in Regulation (EU) 2017/1129 (the “Prospectus Regulation”); and

(B) the expression “offer” includes the communication in any form and by any means of sufficient information on the terms of the offer and the Securities to be offered so as to enable an investor to decide to purchase or subscribe for the Securities.

6. Conditions of Underwriters’ Obligations. The obligation of each Underwriter to purchase Securities on the Closing Date as provided herein is subject to the performance by the Company of its covenants and other obligations hereunder and to the following additional conditions:

(a) Registration Compliance; No Stop Order. No order suspending the effectiveness of the Registration Statement shall be in effect, and no proceeding for such purpose, pursuant to Rule 401(g)(2) or pursuant to Section 8A under the Securities Act shall be pending before or threatened by the Commission; the Prospectus and each Issuer Free Writing Prospectus shall have been timely filed with the Commission under the Securities Act (in the case of an Issuer Free Writing Prospectus, to the extent required by Rule 433 under the Securities Act) and in accordance with Section 4(a) hereof; and all requests by the Commission for additional information shall have been complied with to the reasonable satisfaction of the Representatives.

(b) Representations and Warranties. The representations and warranties of the Company contained herein shall be true and correct on the date hereof and on and as of the Closing Date; and the statements of the Company and its officers made in any certificates delivered pursuant to this Agreement shall be true and correct on and as of the Closing Date.

(c) No Downgrade. Subsequent to the earlier of (A) the Time of Sale and (B) the execution and delivery of this Agreement, (i) no downgrading shall have occurred in the long-term credit rating accorded the Securities or any other senior debt securities of or guaranteed by the Company or any of its subsidiaries by any “nationally recognized statistical rating organization”, as such term is defined under Section 3(a)(62) under the Exchange Act and (ii) no such organization shall have publicly announced that it has under surveillance or review, or has changed its outlook with respect to, its rating of the Securities or any other senior debt securities of or guaranteed by the Company or any of its subsidiaries (other than an announcement with positive implications of a possible upgrading).

(d) No Material Adverse Change. No event or condition of a type described in Section 3(g) hereof shall have occurred or shall exist, which event or condition is not described in the Time of Sale Information (excluding any amendment or supplement thereto) and the Prospectus (excluding any amendment or supplement thereto) and the effect of which in the reasonable judgment of the Representatives (after consultations with the Company among officers) makes it impracticable or inadvisable to proceed with the offering, sale or delivery of the Securities on the terms and in the manner contemplated by this Agreement, the Time of Sale Information and the Prospectus.

(e) Officer’s Certificate. The Representatives shall have received on and as of the Closing Date a certificate of an executive officer, treasurer or controller of the Company who has specific knowledge of the Company’s financial matters and is satisfactory to the Representatives (i) confirming that such officer has carefully reviewed the Registration Statement, the Time of Sale Information and the Prospectus and, to the best knowledge of such officer, the representations set forth in Sections 3(b) and 3(c) hereof are true and correct, (ii) confirming that the other representations and warranties of the Company in this Agreement are true and correct and that the Company has complied with all agreements and satisfied all conditions on its part to be performed or satisfied hereunder at or prior to the Closing Date and (iii) to the effect set forth in paragraphs (a), (c) and (d) above.

(f) Comfort Letters. (i) On the date of this Agreement and on the Closing Date, Deloitte LLP shall have furnished to the Underwriters, at the request of the Company, (A) “SAS 72 comfort letters”, dated the respective dates of delivery thereof and addressed to the Underwriters and (B) “SAS 72 look-alike comfort letters”, dated the respective dates of delivery thereof and addressed to Banco Santander, S.A., BNP Paribas, Citigroup Global Markets Limited, HSBC Bank plc, ICBC Standard Bank Plc, ING Financial Markets LLC, Mizuho International plc, Morgan Stanley & Co. International plc, NatWest Markets Plc and Société Générale, as “Non-US Selling Agents” and affiliates of the Underwriters, in each case in form and substance reasonably satisfactory to the Representatives, containing statements and information of the type customarily included in accountants’ “SAS 72 comfort letters” to underwriters and “SAS 72 look-alike comfort letters” to their affiliates, as applicable, with respect to the financial statements and certain financial information contained or incorporated by reference in the Registration Statement, the Time of Sale Information (as applicable) and the Prospectus; provided that the letters delivered on the Closing Date shall use a “cut-off” date no more than three business days prior to the Closing Date, unless otherwise agreed; (ii) The Company shall have furnished to the Representatives a certificate, dated the Closing Date and addressed to the Representatives, of its chief financial officer with respect to certain data contained in the Registration Statement, the Time of Sale Information and the Prospectus, providing “management comfort” with respect to such information, in form and substance reasonably satisfactory to the Representatives, to the effect set forth in Annex C-1 hereto.

(g) Opinion and 10b-5 Statement of Counsel for the Company. Linklaters LLP, U.S. counsel of the Company shall have furnished to the Representatives, at the request of the Company, their written opinion and 10b-5 statement, dated the Closing Date and addressed to the Underwriters, in form and substance reasonably satisfactory to the Representatives, to the effect set forth in Annex C-2 and Annex C-3, respectively, hereto.

(h) Opinion of United Kingdom Counsel for the Company. Linklaters LLP, United Kingdom counsel for the Company, shall have furnished to the Representatives, at the request of the Company, their written opinion, dated the Closing Date and addressed to the Underwriters, in form and substance reasonably satisfactory to the Representatives, to the effect set forth in Annex C-4, respectively, hereto.

(i) Opinion and 10b-5 Statement of Counsel for the Underwriters. The Representatives shall have received on and as of the Closing Date an opinion and 10b-5 statement of Davis Polk & Wardwell London LLP, counsel for the Underwriters, with respect to such matters as the Representatives may reasonably request, and such counsel shall have received such documents and information as they may reasonably request to enable them to pass upon such matters.

(j) No Legal Impediment to Issuance. No action shall have been taken and no statute, rule, regulation or order shall have been enacted, adopted or issued by any federal, state or foreign governmental or regulatory authority that would, as of the Closing Date, prevent the issuance or sale of the Securities; and no injunction or order of any U.S. federal, state or United Kingdom court shall have been issued that would, as of the Closing Date, prevent the issuance or sale of the Securities.

(k) Additional Documents. On or prior to the Closing Date, the Company shall have furnished to the Representatives such further certificates and documents as the Representatives may reasonably request.

All opinions, letters, certificates and evidence mentioned above or elsewhere in this Agreement shall be deemed to be in compliance with the provisions hereof only if they are in form and substance reasonably satisfactory to counsel for the Underwriters.

7. Indemnification and Contribution.

(a) Indemnification of the Underwriters. The Company agrees to indemnify and hold harmless each Underwriter, its affiliates, directors and officers and each person, if any, who controls such Underwriter within the meaning of Section 15 of the Securities Act or Section 20 of the Exchange Act, from and against any and all losses, claims, damages and liabilities (including, without limitation, legal fees and other expenses incurred in connection with any suit, action or proceeding or any claim asserted as such fees and expenses are incurred), joint or several, that arise

out of, or are based upon, (i) any untrue statement or alleged untrue statement of a material fact contained in the Registration Statement, or caused by any omission or alleged omission to state therein a material fact required to be stated therein or necessary in order to make the statements therein, not misleading, or (ii) any untrue statement or alleged untrue statement of a material fact contained in the Prospectus (or any amendment or supplement thereto), any Issuer Free Writing Prospectus or any Time of Sale Information, or caused by any omission or alleged omission to state therein a material fact necessary in order to make the statements therein, in light of the circumstances under which they were made, not misleading, in each case except insofar as such losses, claims, damages or liabilities arise out of, or are based upon, any untrue statement or omission or alleged untrue statement or omission made in reliance upon and in conformity with any Underwriter Supplied Information.

(b) Indemnification of the Company. Each Underwriter agrees, severally and not jointly, to indemnify and hold harmless the Company, its directors, its officers who signed the Registration Statement and each person, if any, who controls the Company within the meaning of Section 15 of the Securities Act or Section 20 of the Exchange Act to the same extent as the indemnity set forth in paragraph (a) above, but only with respect to any losses, claims, damages or liabilities that arise out of, or are based upon, any untrue statement or omission or alleged untrue statement or omission made in reliance upon and in conformity with any information relating to any Underwriter furnished to the Company in writing by such Underwriter through the Representatives expressly for use in the Registration Statement, the Prospectus (or any amendment or supplement thereto), any Issuer Free Writing Prospectus or any Time of Sale Information (the “Underwriter Supplied Information”), it being understood and agreed that the only Underwriter Supplied Information consists of the following: a) the names of the underwriters on the front cover page of the Preliminary Prospectus and the Prospectus; b) the names set forth in the table of Underwriters in the list under the first paragraph of text under the caption “Underwriting” in the Preliminary Prospectus and the Prospectus; and c) the fourth, sixth and seventh paragraphs and the second sentence of the fifth paragraph of text under the caption “Underwriting” in the Preliminary Prospectus and the Prospectus relating to selling concession and reallowance and stabilization.

(c) Notice and Procedures. If any suit, action, proceeding (including any governmental or regulatory investigation), claim or demand shall be brought or asserted against any person in respect of which indemnification may be sought pursuant to either paragraph (a) or (b) above, such person (the “Indemnified Person”) shall promptly notify the person against whom such indemnification may be sought (the “Indemnifying Person”) in writing; provided that the failure to notify the Indemnifying Person shall not relieve it from any liability that it may have under this Section 7 except to the extent that it has been materially prejudiced (through the forfeiture of substantive rights or defenses) by such failure; and provided further, that the failure to notify the Indemnifying Person shall not relieve it from any liability that it may have to an Indemnified Person otherwise than under this Section 7. If any such

proceeding shall be brought or asserted against an Indemnified Person and it shall have notified the Indemnifying Person thereof, the Indemnifying Person shall retain counsel reasonably satisfactory to the Indemnified Person to represent the Indemnified Person and any others entitled to indemnification pursuant to this Section 7 that the Indemnifying Person may designate in such proceeding and shall pay the fees and expenses of such counsel related to such proceeding as incurred. In any such proceeding, any Indemnified Person shall have the right to retain its own counsel, but the fees and expenses of such counsel shall be at the expense of such Indemnified Person unless (i) the Indemnifying Person and the Indemnified Person shall have mutually agreed to the contrary; (ii) the Indemnifying Person has failed within a reasonable time to retain counsel reasonably satisfactory to the Indemnified Person; (iii) the Indemnified Person shall have reasonably concluded that there may be legal defenses available to it that are different from or in addition to those available to the Indemnifying Person; or (iv) the named parties in any such proceeding (including any impleaded parties) include both the Indemnifying Person and the Indemnified Person and representation of both parties by the same counsel would be inappropriate due to actual or potential differing interests between them. It is understood and agreed that the Indemnifying Person shall not, in connection with any proceeding or related proceeding in the same jurisdiction, be liable for the fees and expenses of more than one separate firm (in addition to any local counsel) for all Indemnified Persons, and that all such fees and expenses shall be reimbursed as they are incurred. Any such separate firm for any Underwriter, its affiliates, directors and officers and any control persons of such Underwriter shall be designated in writing by the Representatives and any such separate firm for the Company, its directors, its officers who signed the Registration Statement and any control persons of the Company shall be designated in writing by the Company. The Indemnifying Person shall not be liable for any settlement of any proceeding effected without its written consent, but if settled with such consent or if there be a final judgment for the plaintiff, the Indemnifying Person agrees to indemnify each Indemnified Person from and against any loss or liability by reason of such settlement or judgment. Notwithstanding the foregoing sentence, if at any time an Indemnified Person shall have requested that an Indemnifying Person reimburse the Indemnified Person for fees and expenses of counsel as contemplated by this paragraph, the Indemnifying Person shall be liable for any settlement of any proceeding effected without its written consent if (i) such settlement is entered into more than 30 days after receipt by the Indemnifying Person of such request and (ii) the Indemnifying Person shall not have reimbursed the Indemnified Person in accordance with such request prior to the date of such settlement. No Indemnifying Person shall, without the written consent of the Indemnified Person, effect any settlement of any pending or threatened proceeding in respect of which any Indemnified Person is or could have been a party and indemnification could have been sought hereunder by such Indemnified Person, unless such settlement (x) includes an unconditional release of such Indemnified Person, in form and substance reasonably satisfactory to such Indemnified Person, from all liability on claims that are the subject matter of such proceeding and (y) does not include any statement as to or any admission of fault, culpability or a failure to act by or on behalf of any Indemnified Person.

(d) Contribution. If the indemnification provided for in paragraphs (a) and (b) above is unavailable to an Indemnified Person or insufficient in respect of any losses, claims, damages or liabilities referred to therein, then each Indemnifying Person under such paragraph, in lieu of indemnifying such Indemnified Person thereunder, shall contribute to the amount paid or payable by such Indemnified Person as a result of such losses, claims, damages or liabilities (i) in such proportion as is appropriate to reflect the relative benefits received by the Company on the one hand and the Underwriters on the other from the offering of the Securities or (ii) if the allocation provided by clause (i) is not permitted by applicable law, in such proportion as is appropriate to reflect not only the relative benefits referred to in clause (i) but also the relative fault of the Company on the one hand and the Underwriters on the other in connection with the statements or omissions that resulted in such losses, claims, damages or liabilities, as well as any other relevant equitable considerations. The relative benefits received by the Company on the one hand and the Underwriters on the other shall be deemed to be in the same respective proportions as the net proceeds (before deducting expenses) received by the Company from the sale of the Securities and the total underwriting discounts and commissions received by the Underwriters in connection therewith, in each case as set forth in the table on the cover of the Prospectus, bear to the aggregate offering price of the Securities. The relative fault of the Company on the one hand and the Underwriters on the other shall be determined by reference to, among other things, whether the untrue or alleged untrue statement of a material fact or the omission or alleged omission to state a material fact relates to information supplied by the Company or by the Underwriters and the parties’ relative intent, knowledge, access to information and opportunity to correct or prevent such statement or omission.

(e) Limitation on Liability. The Company and the Underwriters agree that it would not be just and equitable if contribution pursuant to this Section 7 were determined by pro rata allocation (even if the Underwriters were treated as one entity for such purpose) or by any other method of allocation that does not take account of the equitable considerations referred to in paragraph (d) above. The amount paid or payable by an Indemnified Person as a result of the losses, claims, damages and liabilities referred to in paragraph (d) above shall be deemed to include, subject to the limitations set forth above, any legal or other expenses incurred by such Indemnified Person in connection with any such action or claim. Notwithstanding the provisions of this Section 7, in no event shall an Underwriter be required to contribute any amount in excess of the amount by which the total underwriting discounts and commissions received by such Underwriter with respect to the offering of the Securities exceeds the amount of any damages that such Underwriter has otherwise been required to pay by reason of such untrue or alleged untrue statement or omission or alleged omission. No person guilty of fraudulent misrepresentation (within the meaning of Section 11(f) of the Securities Act) shall be entitled to contribution from any person who was not guilty of such fraudulent misrepresentation. The Underwriters’ obligations to contribute pursuant to this Section 7 are several in proportion to their respective purchase obligations hereunder and not joint.

(f) Non-Exclusive Remedies. The remedies provided for in this Section 7 are not exclusive and shall not limit any rights or remedies which may otherwise be available to any Indemnified Person at law or in equity.

8. Effectiveness of Agreement. This Agreement shall become effective as of the date first written above.

9. Termination. This Agreement may be terminated in the discretion of the Representatives by notice to the Company, if after the execution and delivery of this Agreement and prior to the Closing Date (i) trading generally shall have been suspended or materially limited on the Exchange or the London Stock Exchange; (ii) trading of any securities issued or guaranteed by the Company shall have been suspended on any exchange; (iii) a general moratorium on commercial banking activities shall have been declared by U.S. federal or New York State authorities or authorities in the United Kingdom; (iv) there shall have occurred any outbreak or escalation of hostilities or any change in financial markets or any calamity or crisis, involving the United States or the United Kingdom, that, in the reasonable judgment of the Representatives (after consultations to the extent predictable with the Company), is so material and adverse as to make it impracticable or inadvisable to proceed with the offering, sale or delivery of the Securities on the terms and in the manner contemplated by this Agreement, the Time of Sale Information and the Prospectus.

10. Defaulting Underwriter.

(a) If, on the Closing Date, any Underwriter defaults on its obligation to purchase the Securities that it has agreed to purchase hereunder, the non-defaulting Underwriters may in their discretion arrange for the purchase of such Securities by other persons satisfactory to the Company on the terms contained in this Agreement. If, within 36 hours after any such default by any Underwriter, the non-defaulting Underwriters do not arrange for the purchase of such Securities, then the Company shall be entitled to a further period of 36 hours within which to procure other persons satisfactory to the non-defaulting Underwriters to purchase such Securities on such terms. If other persons become obligated or agree to purchase the Securities of a defaulting Underwriter, either the non-defaulting Underwriters or the Company may postpone the Closing Date for up to five full business days in order to effect any changes that in the opinion of counsel for the Company or counsel for the Underwriters may be necessary in the Registration Statement, the Time of Sale Information and the Prospectus or in any other document or arrangement, and the Company agrees to promptly prepare any amendment or supplement to the

Registration Statement, the Time of Sale Information and the Prospectus that effects any such changes. As used in this Agreement, the term “Underwriter” includes, for all purposes of this Agreement unless the context otherwise requires, any person not listed in Schedule 1 hereto that, pursuant to this Section 10, purchases Securities that a defaulting Underwriter agreed but failed to purchase.

(b) If, after giving effect to any arrangements for the purchase of the Securities of a defaulting Underwriter or Underwriters by the non-defaulting Underwriters and the Company as provided in paragraph (a) above, the aggregate principal amount of such Securities that remains unpurchased does not exceed one-eleventh of the aggregate principal amount of all the Securities, then the Company shall have the right to require each non-defaulting Underwriter to purchase the principal amount of Securities that such Underwriter agreed to purchase hereunder plus such Underwriter’s pro rata share (based on the principal amount of Securities that such Underwriter agreed to purchase hereunder) of the Securities of such defaulting Underwriter or Underwriters for which such arrangements have not been made.

(c) If, after giving effect to any arrangements for the purchase of the Securities of a defaulting Underwriter or Underwriters by the non-defaulting Underwriters and the Company as provided in paragraph (a) above, the aggregate principal amount of such Securities that remains unpurchased exceeds one-eleventh of the aggregate principal amount of all the Securities, or if the Company shall not exercise the right described in paragraph (b) above, then this Agreement shall terminate without liability on the part of the non-defaulting Underwriters. Any termination of this Agreement pursuant to this Section 10 shall be without liability on the part of the Company, except that the Company will continue to be liable for the payment of expenses as set forth in Section 11 hereof and except that the provisions of Section 7 hereof shall not terminate and shall remain in effect.

(d) Nothing contained herein shall relieve a defaulting Underwriter of any liability it may have to the Company or any non-defaulting Underwriter for damages caused by its default.

11. Payment of Expenses.

(a) Whether or not the transactions contemplated by this Agreement are consummated or this Agreement is terminated, the Company will pay or cause to be paid all costs and expenses incident to the performance of its obligations hereunder, including without limitation, (i) the costs incident to the authorization, issuance, sale, preparation and delivery of the Securities and any taxes payable in that connection; (ii) the costs incident to the preparation, printing and filing under the Securities Act of the Registration Statement, the Preliminary Prospectus, any Issuer Free Writing Prospectus, any Time of Sale Information and the Prospectus (including all exhibits, amendments and supplements thereto) and the distribution thereof; (iii) the costs of

reproducing and distributing each of the Transaction Documents; (iv) the fees and expenses of the Company’s counsel and independent accountants; (v) the fees and expenses incurred in connection with the registration or qualification and determination of eligibility for investment of the Securities under the laws of such jurisdictions as the Representatives may designate; (vi) any fees charged by rating agencies for rating the Securities; (vii) the fees and expenses of the Trustee and any paying agent (including related fees and expenses of any counsel to such parties); (viii) all expenses incurred by the Company in connection with any “road show” presentation to potential investors and (ix) all expenses and application fees related to the listing of the Securities on the Exchange.

(b) If (i) this Agreement is terminated pursuant to Section 9, (ii) the Company for any reason fails to tender the Securities for delivery to the Underwriters or (iii) the Underwriters decline to purchase the Securities for any reason permitted under this Agreement, the Company agrees to reimburse the Underwriters for all out-of-pocket costs and expenses (including the fees and expenses of their counsel) reasonably incurred by the Underwriters in connection with this Agreement and the offering contemplated hereby.

12. Persons Entitled to Benefit of Agreement. This Agreement shall inure to the benefit of and be binding upon the parties hereto and their respective successors and the officers and directors and any controlling persons referred to herein, and the affiliates of each Underwriter referred to in Section 7 hereof. Nothing in this Agreement is intended or shall be construed to give any other person any legal or equitable right, remedy or claim under or in respect of this Agreement or any provision contained herein. No purchaser of Securities from any Underwriter shall be deemed to be a successor merely by reason of such purchase.

13. Survival. The respective indemnities, rights of contribution, representations, warranties and agreements of the Company and the Underwriters contained in this Agreement or made by or on behalf of the Company or the Underwriters pursuant to this Agreement or any certificate delivered pursuant hereto shall survive the delivery of and payment for the Securities and shall remain in full force and effect, regardless of any termination of this Agreement or any investigation made by or on behalf of the Company or the Underwriters.

14. Certain Defined Terms. For purposes of this Agreement, (a) except where otherwise expressly provided, the term “affiliate” has the meaning set forth in Rule 405 under the Securities Act; (b) the term “business day” means any day other than a day on which banks are permitted or required to be closed in New York City or London; (c) the term “subsidiaries” has the meaning set forth in Rule 405 under the Securities Act; and (d) the term “principal subsidiaries” means National Grid Electricity Distribution Holdings plc, National Grid Electricity Transmission plc, National Grid USA, National Grid North America Inc., National Grid Holdings One plc and Niagara Mohawk Power Corporation.

15. Compliance with USA Patriot Act. In accordance with the requirements of the USA Patriot Act (Title III of Pub. L. 107-56 (signed into law October 26, 2001)), the Underwriters are required to obtain, verify and record information that identifies their respective clients, including the Company, which information may include the name and address of their respective clients, as well as other information that will allow the Underwriters to properly identify their respective clients.

16. Consent to Jurisdiction.

(a) The Company irrevocably consents and agrees, for the benefit of the Underwriters, that any legal action, suit or proceeding against it with respect to its obligations, liabilities or any other matter arising out of or in connection with this Agreement may be brought in the courts of the State of New York or the courts of the United States of America located in the Borough of Manhattan, The City of New York and hereby irrevocably consents and submits to the non-exclusive jurisdiction of each such court in personam, generally and unconditionally with respect to any action, suit or proceeding for itself and in respect of its properties, assets and revenues.

(b) The Company hereby irrevocably designates, appoints, and empowers Corporation Service Company with offices at 19 West 44th Street, Suite 200, New York, NY 10036, as its designee, appointee and agent to receive, accept and acknowledge for and on its behalf, and its properties, assets and revenues, service of any and all legal process, summons, notices and documents which may be served in any such action, suit or proceeding brought in any such United States or state court which may be made on such designee, appointee and agent in accordance with legal procedures prescribed for such courts. If for any reason such designee, appointee and agent hereunder shall cease to be available to act as such, the Company agrees to designate a new designee, appointee and agent in The City of New York on the terms and for the purposes of this Section 16 satisfactory to the Representatives. The Company further hereby irrevocably consents and agrees to the service of any and all legal process, summons, notices and documents out of any of the aforesaid courts in any such action, suit or proceeding by serving a copy thereof upon the relevant agent for service of process referred to in this Section 16 (whether or not the appointment of such agent shall for any reason prove to be ineffective or such agent shall accept or acknowledge such service) or by mailing copies thereof by registered or certified air mail, first class, postage prepaid, to each of them at their respective addresses specified in or designated pursuant to this Agreement. The Company agrees that the failure of any such designee, appointee and agent to give any notice of such service to it shall not impair or affect in any way the validity of such service or any judgment rendered in any action or proceeding based thereon. Nothing herein shall in any way be deemed to limit the ability of any Underwriter to serve any such legal process, summons, notices and documents in any other manner permitted by applicable law or to obtain jurisdiction over the undersigned or bring actions, suits or proceedings against the undersigned in any jurisdictions, and in any manner, as may be permitted by applicable law. The Company hereby irrevocably and

unconditionally waives, to the fullest extent permitted by law, any objection which it may now or hereafter have to the laying of venue of any of the aforesaid actions, suits or proceedings arising out of or in connection with this Agreement brought in the United States federal courts or the courts of the State of New York located in the Borough of Manhattan, The City of New York and hereby further irrevocably and unconditionally waives and agrees not to plead or claim in any such court that any such action, suit or proceeding brought in any such court has been brought in an inconvenient forum.

17. Miscellaneous.

(a) Authority of the Representatives. Any action by the Underwriters hereunder may be taken by the Representatives on behalf of the Underwriters, and any such action taken by the Representatives shall be binding upon the Underwriters.

(b) Notices. All notices and other communications hereunder shall be in writing and shall be deemed to have been duly given if mailed or transmitted and confirmed by any standard form of telecommunication. Notices to the Underwriters shall be given to the Representatives as follows:

BNP Paribas Securities Corp.

787 Seventh Avenue

New York, NY 10019

United States of America

Attention: Debt Syndicate Desk

Email: DL.US.Syndicate.Support@us.bnpparibas.com

Citigroup Global Markets Inc.

388 Greenwich Street

New York, NY 10013

United States of America

Attention: General Counsel

Fax: 646-291-1469

Mizuho Securities USA LLC

1271 Avenue of the Americas

New York, NY 10020

United States of America

Attn: Debt Capital Markets

Email: legalnotices@mizuhogroup.com

Morgan Stanley & Co. LLC

1585 Broadway, 29th Floor

New York, NY 10036

United States of America

Attention: Investment Banking Division

Fax: (212) 507-8999

Notices to the Company shall be given to it at:

National Grid USA

2 Hanson Place

Brooklyn, NY 11217

United States of America

Email: treasurybackoffice@nationalgrid.com

Attention: Treasurer

With a copy to:

Linklaters LLP

1290 Avenue of the Americas

New York, NY 10104

United States of America

Email: jeffrey.cohen@linklaters.com

Attention: Jeffrey Cohen

(c) Governing Law. This Agreement shall be governed by and construed in accordance with the laws of the State of New York.

(d) Waiver of Jury Trial. Each of the parties hereto hereby waives any right to trial by jury in any suit or proceeding arising out of or relating to this Agreement.

(e) Recognition of the U.S. Special Resolution Regimes.

(i) In the event that any Underwriter that is a Covered Entity becomes subject to a proceeding under a U.S. Special Resolution Regime, the transfer from such Underwriter of this Agreement, and any interest and obligation in or under this Agreement, will be effective to the same extent as the transfer would be effective under the U.S. Special Resolution Regime if this Agreement, and any such interest and obligation, were governed by the laws of the United States or a state of the United States.

(ii) In the event that any Underwriter that is a Covered Entity or a BHC Act Affiliate of such Underwriter becomes subject to a proceeding under a U.S. Special Resolution Regime, Default Rights under this Agreement that may be exercised against such Underwriter are permitted to be exercised to no greater extent than such Default Rights could be exercised under the U.S. Special Resolution Regime if this Agreement were governed by the laws of the United States or a state of the United States.

As used in this Section 17(e):

“BHC Act Affiliate” has the meaning assigned to the term “affiliate” in, and shall be interpreted in accordance with, 12 U.S.C. § 1841(k).

“Covered Entity” means any of the following:

(i) a “covered entity” as that term is defined in, and interpreted in accordance with, 12 C.F.R. § 252.82(b);

(ii) a “covered bank” as that term is defined in, and interpreted in accordance with, 12 C.F.R. § 47.3(b); or

(iii) a “covered FSI” as that term is defined in, and interpreted in accordance with, 12 C.F.R. § 382.2(b).

“Default Right” has the meaning assigned to that term in, and shall be interpreted in accordance with, 12 C.F.R. §§ 252.81, 47.2 or 382.1, as applicable.

“U.S. Special Resolution Regime” means each of (i) the Federal Deposit Insurance Act and the regulations promulgated thereunder and (ii) Title II of the Dodd-Frank Wall Street Reform and Consumer Protection Act and the regulations promulgated thereunder.

(f) Counterparts; Effectiveness. This Agreement may be executed in two or more counterparts, each of which shall be deemed an original, but all of which taken together shall constitute one and the same agreement, it being understood that all of the parties need not sign the same counterpart. Counterparts may be delivered via facsimile, electronic mail (including .pdf or any electronic signature complying with the U.S. federal ESIGN Act of 2000, e.g., www.docusign.com) or other transmission method and any counterpart so delivered shall be deemed to have been duly and validly delivered and be valid and effective as delivery of a manually executed counterpart of this Agreement. Each of the parties hereto represents that it has undertaken commercially reasonable steps to verify the identity of each individual person executing any such counterparts via electronic signature on behalf of such party and has and will maintain sufficient records of the same. This Agreement shall become effective when each party shall have received a counterpart hereof signed by all of the other parties hereto.

(g) Amendments or Waivers. No amendment or waiver of any provision of this Agreement, nor any consent or approval to any departure therefrom, shall in any event be effective unless the same shall be in writing and signed by the parties hereto.

(h) Headings. The headings herein are included for convenience of reference only and are not intended to be part of, or to affect the meaning or interpretation of, this Agreement.

(i) Judgment Currency. The Company agrees to indemnify each Underwriter, its directors, officers, affiliates and each person, if any, who controls such Underwriter within the meaning of Section 15 of the Securities Act or Section 20 of the Exchange Act, against any loss incurred by such Underwriter as a result of any judgment or order being given or made for any amount due hereunder and such judgment or order being expressed and paid in a currency (the “judgment currency”) other than U.S. dollars and as a result of any variation as between (i) the rate of exchange at which the U.S. dollar amount is converted into the judgment currency for the purpose of such judgment or order, and (ii) the rate of exchange at which such indemnified person is able to purchase U.S. dollars with the amount of the judgment currency actually received by the indemnified person. The foregoing indemnity shall constitute a separate and independent obligation of the Company and shall continue in full force and effect notwithstanding any such judgment or order as aforesaid. The term “rate of exchange” shall include any premiums and costs of exchange payable in connection with the purchase of, or conversion into, the relevant currency.

[Signature page follows]

If the foregoing is in accordance with your understanding, please indicate your acceptance of this Agreement by signing in the space provided below.

Accepted as of the date first written above:

For themselves and on behalf of the

several Underwriters listed

in Schedule 1 hereto.

Schedule 1

Annex A

Time of Sale Information

Annex B

National Grid plc

U.S.$750,000,000 5.418% Notes due 2034

Pricing Term Sheet

No PRIIPs or UK PRIIPs key information document (KID) has been prepared as not available to retail in EEA or UK.

Capitalized terms used but not defined in this term sheet have the meanings set forth in the base prospectus as supplemented by the preliminary prospectus supplement.

ICBC Standard Bank Plc is restricted in its U.S. securities dealings under the United States Bank Holding Company Act and may not underwrite, subscribe, agree to purchase or procure purchasers to purchase notes that are offered or sold in the United States. Accordingly, ICBC Standard Bank Plc shall not be obligated to, and shall not, underwrite, subscribe, agree to purchase or procure purchasers to purchase notes that may be offered or sold by other underwriters in the United States. ICBC Standard Bank Plc shall offer and sell the Notes constituting part of its allotment solely outside the United States.

The issuer has filed a registration statement (including a prospectus) with the SEC for the offering to which this communication relates. Before you invest, you should read the prospectus in that registration statement and other documents the issuer has filed with the SEC for more complete information about the issuer and this offering. You may get these documents for free by visiting EDGAR on the SEC website at www.sec.gov. Alternatively, you may obtain a copy of the base prospectus and the preliminary prospectus supplement by calling toll-free BNP Paribas Securities Corp. at 1-800-854-5674, Citigroup Global Markets Inc. at 1-800-831-9146, Mizuho Securities USA LLC at 1-866-271-7403 or Morgan Stanley & Co. LLC at 1-866-718-1649.

Annex C-1

Form of Chief Financial Officer’s Certificate

Annex C-2

Form of Opinion of Counsel for the Company

Annex C-3

Form of 10b-5 Statement of Counsel for the Company

Annex C-4

Form of Opinion of United Kingdom Counsel for the Company

Exhibit 4.1

SECOND SUPPLEMENTAL INDENTURE

by and between

NATIONAL GRID PLC,

the Company

and

THE BANK OF NEW YORK MELLON, LONDON BRANCH,

as Trustee and Paying Agent

relating to an Indenture, dated as of June 12, 2023

January 11, 2024

Table of Contents

i

This Second Supplemental Indenture, dated as of January 11, 2024 (this “Second Supplemental Indenture”), between National Grid plc, a company incorporated under the laws of England and Wales (the “Company”) and The Bank of New York Mellon, London Branch, a New York banking corporation organized and existing under the laws of New York, acting through its London Branch, as trustee (the “Trustee”, which term includes any successor Trustee) and paying agent (the “Paying Agent”, which term includes any successor Paying Agent).

Whereas, the Company has heretofore entered into an Indenture, dated as of June 12, 2023 (as may be amended and supplemented from time to time, the “Indenture”) with the Trustee;

Whereas, pursuant to Sections 3.1 and 10.1 of the Indenture, the Company proposes to create new series of Securities under the Indenture;

Whereas, the Company hereby resolves to issue the Designated Securities (as such term is defined in Section 2.1 hereof) in an aggregate principal amount of $750,000,000, and with the terms and conditions set forth in this Second Supplemental Indenture; and all things necessary to make this Second Supplemental Indenture a valid and binding agreement of the Company, in accordance with its terms, have been done;

Now, therefore, for and in consideration of the premises and the purchases of the Designated Securities by the Holders thereof, it is mutually covenanted and agreed, for the equal and proportionate benefit of all Holders of Designated Securities, as follows:

ARTICLE 1

DEFINITIONS AND OTHER PROVISIONS OF GENERAL APPLICATION

SECTION 1.1 Definitions. For purposes of this Second Supplemental Indenture, except as otherwise expressly provided or unless the context otherwise requires:

(a) the terms defined herein have the meanings assigned to them herein and include the plural as well as the singular;

(b) all other terms used herein which are defined in the Trust Indenture Act, either directly or by reference therein, have the meanings assigned to them therein;

(c) unless the context otherwise requires, any reference to an “Article” or a “Section” refers to an Article or a Section, as the case may be, of this Second Supplemental Indenture;

(d) the words “herein”, “hereof” and “hereunder” and other words of similar import refer to this Second Supplemental Indenture as a whole and not to any particular Article, Section or other subdivision; and

(e) all terms used but not defined in this Second Supplemental Indenture, which are defined in the Indenture, shall have the meanings assigned to them in the Indenture.

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SECTION 1.2 Conflict with Trust Indenture Act. If and to the extent that any provision hereof limits, qualifies or conflicts with a provision of the Trust Indenture Act that is required under such Act to be a part of and govern the Indenture, the provision of the Trust Indenture Act shall control. If any provision of this Second Supplemental Indenture modifies or excludes any provision of the Trust Indenture Act that may be so modified or excluded, the provision of the Trust Indenture Act shall be deemed to apply to this Second Supplemental Indenture as so modified or excluded, as the case may be.

SECTION 1.3 Effect of Headings and Table of Contents. The Article and Section headings herein and the Table of Contents are for convenience only and shall not affect the construction hereof.

SECTION 1.4 Successors and Assigns. All covenants and agreements by the Company in this Second Supplemental Indenture shall bind its successors and assigns, whether so expressed or not.

SECTION 1.5 Separability Clause. In case any provision in this Second Supplemental Indenture shall be invalid, illegal or unenforceable, the validity, legality and enforceability of the remaining provisions shall not in any way be affected or impaired thereby.

SECTION 1.6 Benefits of Supplemental Indenture. Nothing in the Indenture or the Designated Securities, express or implied, shall give to any Person, other than the parties hereto and their successors hereunder and the Holders of Designated Securities, any benefit or any legal or equitable right, remedy or claim under the Indenture.

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SECTION 1.7 Governing Law. Pursuant to Section 5-1401 of the General Obligations Law of the State of New York, this Second Supplemental Indenture shall be governed by, and construed in accordance with, the laws of the State of New York.

SECTION 1.8 Execution in Counterparts. This Second Supplemental Indenture may be executed in any number of counterparts by manual, facsimile or electronic signature, provided that any electronic signature is a true representation of the signer’s actual signature, each of which so executed shall be deemed to be an original, but all such counterparts shall together constitute but one and the same instrument, and signature pages may be delivered by facsimile, electronic mail (including any electronic signature complying with the U.S. federal ESIGN Act of 2000, Uniform Electronic Transaction Act, the New York Electronic Signatures and Records Act (N.Y. State Tech. §§ 301-309), as amended from time to time, or other applicable law) or other transmission method.

SECTION 1.9 Recitals by the Company. The recitals in this Second Supplemental Indenture are made by the Company only and not by the Trustee, and all of the provisions contained in the Indenture in respect of the rights, privileges, immunities, powers and duties of the Trustee shall be applicable in respect of this Second Supplemental Indenture as fully and with like effect as if set forth herein in full.

SECTION 1.10 Ratification and Incorporation of Indenture. As supplemented hereby, the Indenture is in all other respects ratified and confirmed, and from this day forward, references to the Indenture shall mean the Indenture as amended and supplemented by this Second Supplemental Indenture.

ARTICLE 2

THE SECURITIES

SECTION 2.1 Creation of Designated Securities. There is hereby created a new series of Securities to be issued under the Indenture to be designated as 5.418% Notes due 2034 (the “Designated Securities”).

SECTION 2.2 Limitation on Aggregate Principal Amount of Designated Securities. The aggregate principal amount of the Designated Securities shall initially be limited to $750,000,000 (except for Designated Securities represented by any Security certificate authenticated and delivered upon registration of transfer of, or in exchange for, or in lieu of, other Designated Securities pursuant to Section 3.6, 3.7, Section 3.9 or Section 10.6 of the Indenture and except for any Designated Securities which, pursuant to Section 3.3 of the Indenture, are deemed never to have been authenticated and delivered under the Indenture). The Company may from time to time, without the consent of the Holders of a series of Designated Securities, create and issue further securities having the same terms and conditions as such previously issued series of Designated Securities in all respects (or in all respects except for the issue date, the first payment of interest thereon and/or issue price), so that such further issue shall be consolidated and form a single series with the relevant series of Outstanding Designated Securities; provided, however, that any such further issuance will only be made if either such additional securities are issued with no more than de minimis original issue discount for U.S. federal income tax purposes or any such further issuance is a “qualified reopening” as such term is defined under Treasury Regulations Section 1.1275-2(k)(3) promulgated under the Internal Revenue Code of 1986, as amended.

SECTION 2.3 Payment of Principal.SECTION 2.4 The principal of the Designated Securities shall be due and payable at the Stated Maturity.

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SECTION 2.4 Interest and Interest Rate.

(a) The Designated Securities will bear interest from January 11, 2024, or from the most recent date through which the Company has paid or provided for interest on the Designated Securities, at an annual rate of 5.418%.

(b) The Company will pay interest on the Designated Securities semi-annually on each January 11 and July 11 of each year, beginning on July 11, 2024 until and including at Maturity (each an “Interest Payment Date”).

(c) Interest on the Designated Securities will be computed on the basis of a 360-day year consisting of twelve 30-day months. Except as described below for the first Interest Payment Date, on each Interest Payment Date, the Company will pay interest on the Designated Securities for the period commencing on and including the immediately preceding Interest Payment Date and ending on and including the day immediately preceding that Interest Payment Date.

(d) On the first Interest Payment Date, the Company will pay interest for the period beginning on and including the issue date of the Designated Securities and ending on and excluding the first Interest Payment Date.

(e) If any Interest Payment Date would fall on a day that is not a Business Day, the interest payment shall be postponed to the next day that is a Business Day, and no interest on such payment shall accrue for the period from and after such Interest Payment Date.

(f) If the Maturity of any Designated Security is not a Business Day, payment of principal and interest on the applicable Designated Security will be made on the next succeeding day that is a Business Day, and no interest will accrue for the period from and after such Maturity.

(g) Interest on each Designated Security will be paid only to the Person in whose name such Designated Security was registered at the close of business on the Regular Record Date for the applicable Interest Payment Date, which shall be the 15th calendar day preceding such Interest Payment Date, whether or not such day is a Business Day.

SECTION 2.5 Paying Agent

(a) Upon the terms and subject to the conditions contained herein, the Company hereby appoints The Bank of New York Mellon, London Branch as the initial Paying Agent under the Indenture for the purpose of performing the functions of the Paying Agent with respect to the Designated Securities.

(b) The Paying Agent shall exercise due care in performing the functions of the Paying Agent for the Designated Securities.

(c) The Paying Agent accepts its obligations set forth herein, upon the terms and subject to the conditions hereof, including the following, to all of which the Company agrees:

(i) The Paying Agent shall be entitled to such compensation as may be agreed in writing with the Company for all services rendered by the Paying Agent, and the Company promises to pay such compensation and to reimburse the Paying Agent for the reasonable out-of-pocket expenses (including reasonable counsel fees and expenses) properly incurred by it in connection with the services rendered by it hereunder upon receipt of such invoices as the Company shall reasonably require. The Company agrees to indemnify the Paying Agent for, and to hold it harmless against, any and all loss, liability, damage, claims or reasonable expenses (including the costs and expenses of defending against any claim of liability) properly incurred by the Paying Agent that arises out of or in connection with its acting as Paying Agent hereunder, except such as may result from the negligence, willful misconduct or bad faith of the Paying Agent or any of its agents or employees. The Paying Agent shall

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incur no liability and shall be indemnified and held harmless by the Company for, or in respect of, any action taken or omitted by it in good faith in reliance upon written instructions from the Company. The provisions of this paragraph shall survive the termination of this Second Supplemental Indenture.

(ii) In acting under the Indenture and in connection with the Designated Securities, the Paying Agent is acting solely as agent of the Company and does not assume any obligations to, or relationship of agency or trust for or with, any of the Holders of the Designated Securities.

(iii) The Paying Agent shall be protected and shall incur no liability for or in respect of any action taken or omitted to be taken or anything suffered by it in reliance upon the terms of the Designated Securities resolution, Officer’s Certificate or any other certificate, statement, instrument, opinion, report, notice, request, consent, order, bond, debenture, note, coupon, security or other paper or document (whether in original or facsimile form) believed by it to be genuine and to have been signed or presented by the proper party or parties. (iv) The duties and obligations of the Paying Agent shall be determined solely by the express provisions of the Indenture, and the Paying Agent shall not be liable except for the performance of such duties and obligations as are specifically set forth in the Indenture, and no implied covenants or obligations shall be read into the Indenture against the Paying Agent.

(v) Unless herein otherwise specifically provided, any request, direction, order or demand of the Company mentioned herein shall be sufficiently evidenced by an Officer’s Certificate (unless other evidence in respect thereof be herein specifically prescribed).

(vi) The Paying Agent may, upon obtaining the prior written consent of the Company (which consent shall not be unreasonably withheld) perform any duties hereunder either directly or by or through agents or attorneys not regularly in its employ, and the Paying Agent shall not be responsible for any misconduct or negligence on the part of any such agent or attorney appointed with due care by it hereunder.

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(ii) Any successor Paying Agent appointed hereunder shall execute and deliver to its predecessor and to the Company an instrument accepting such appointment hereunder, and thereupon such successor Paying Agent, without any further act, deed or conveyance, shall become vested with all the authority, rights, powers, trusts, immunities, duties and obligations of such predecessor with like effect as if originally named as such Paying Agent hereunder, and such predecessor, upon payment of its charges and disbursements then unpaid, shall thereupon become obliged to transfer and deliver, and such successor Paying Agent shall be entitled to receive, copies of any relevant records maintained by such predecessor Paying Agent.

(iii) Any Person into which the Paying Agent may be merged or converted or with which the Paying Agent may be consolidated, or any Person resulting from any merger, conversion or consolidation to which the Paying Agent shall be a party, or any Person succeeding to all or substantially all of the assets and business of the Paying Agent, or all or substantially all of the corporate trust business of the Paying Agent shall, to the extent permitted by applicable law and provided that it shall have an established place of business in New York, New York, be the successor Paying Agent under the Indenture without the execution or filing of any paper or any further act on the part of any of the parties hereto. Notice of any such merger, conversion, consolidation or sale shall forthwith be given to the Company within 30 days of such merger, conversion, consolidation or sale.

(iv) Any notice required to be given by the Paying Agent to any other Person hereunder shall be given in accordance with Section 13.5 of the Indenture. Any notice to be given to the Paying Agent shall be delivered in person, sent by letter or communicated by telephone (subject, in the case of communications by telephone, to confirmation dispatched within twenty-four hours by letter), to the following address (or to any other address of which the Paying Agent shall have notified the others in writing): Corporate Trust Administration, The Bank of New York Mellon, London Branch, Corporate Trust Services, 160 Queen Victoria Street, London EC4V 4LA, United Kingdom, Email: corpsov1@bnymellon.com. Any notice hereunder given by telephone or letter shall be deemed to be received when in the ordinary course of transmission or post, as the case may be, it would be received.

SECTION 2.6 Place of Payment.

The place or places where, subject to the provisions of Section 4.2 of the Indenture, the principal of, and any premium and interest on, and any Additional Amounts in respect of, the Designated Securities shall be payable, Security certificates representing the Designated Securities may be surrendered for exchange or conversion of the Designated Securities represented thereby and notices and demands to or upon the Company in respect of the Designated Securities and the Indenture may be served shall be the Corporate Trust Office of the Trustee, or at the Trustee’s offices at Corporate Trust Administration, The Bank of New York Mellon, London Branch, Corporate Trust Services, 160 Queen Victoria Street, London EC4V 4LA, United Kingdom, Email: corpsov1@bnymellon.com.

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SECTION 2.7 Denominations.

The Designated Securities may be issued in denominations of $2,000 and integral multiples of $1,000.

SECTION 2.8 Security Certificates.

(a) The Designated Securities shall initially be represented by one or more Global Securities substantially in the form of Exhibit A hereto, which shall be deposited with a custodian for the Depository and the Designated Securities represented thereby will be registered in the name of a nominee of the Depository, for the accounts of participants in the Depository.

(b) Designated Securities represented by a Global Security may be transferred, in whole and not in part, only to another nominee of the Depository, to the Depository by a nominee of the Depository, or by a nominee to another nominee of such Depository or, in either case, to a successor Depository selected or approved by the Company or to a nominee of such successor Depository.

(c) Beneficial interests in any Designated Securities represented by a Global Security will be exchangeable for Designated Securities represented by definitive Securities only if: (i) the Depository notifies the Company that it is unwilling or unable to continue to act as Depository or that it is no longer registered in good standing under the Exchange Act or other applicable statute or regulation and, in either case, a successor Depository is not appointed by the Company within 120 days after the date of such notice from the Depository or (ii) the Company notifies the Trustee in writing that it has determined in its sole discretion that the Designated Securities shall no longer be represented by a Global Security.

(d) Upon the occurrence of any of the events specified in (i) or (ii) of (c) above, Designated Securities represented by definitive Securities shall be (i) delivered by the Trustee in exchange for beneficial interest in Designated Securities represented by Global Securities and (ii) registered in such names, and issued in such authorized denominations, as shall be requested by or on behalf of the Depository in accordance with its customary procedures.

SECTION 2.9 Defeasance and Covenant Defeasance. The provisions of Section 12.2 of the Indenture will apply to the Designated Securities.

SECTION 2.10 Additional Amounts. The provisions of Section 4.4 of the Indenture will apply to the Designated Securities.

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In witness whereof, each of the parties hereto has caused this Second Supplemental Indenture to be duly executed on its behalf as of the date first above written.

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EXHIBIT A

FORM OF SECURITY CERTIFICATE REPRESENTING THE DESIGNATED SECURITIES

NATIONAL GRID PLC

5.418% Notes due 2034

ISIN No. US636274AF94

UNLESS AND UNTIL IT IS EXCHANGED IN WHOLE OR IN PART FOR DEFINITIVE CERTIFICATES, THIS CERTIFICATE MAY BE TRANSFERRED, IN WHOLE AND NOT IN PART, ONLY: (I) BY THE DEPOSITORY TO A NOMINEE OF THE DEPOSITORY, (II) BY A NOMINEE OF THE DEPOSITORY TO THE DEPOSITORY OR TO ANOTHER NOMINEE OF THE DEPOSITORY, OR (III) BY THE DEPOSITORY OR ANY SUCH NOMINEE TO A SUCCESSOR DEPOSITORY OR A NOMINEE OF SUCH SUCCESSOR DEPOSITORY, AND TRANSFERS OF THE SECURITIES REPRESENTED BY THIS CERTIFICATE AND ANY BENEFICIAL INTERESTS IN ANY SECURITIES REPRESENTED BY THIS CERTIFICATE SHALL BE LIMITED TO TRANSFERS MADE IN ACCORDANCE WITH THE RESTRICTIONS SET FORTH IN THE INDENTURE REFERRED TO BELOW.

UNLESS THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITORY TRUST COMPANY, A NEW YORK CORPORATION (“DTC”), TO THE ISSUER OR ITS AGENT FOR REGISTRATION OF TRANSFER, EXCHANGE OR PAYMENT, AND ANY CERTIFICATE ISSUED IS REGISTERED BY AN AUTHORIZED REPRESENTATIVE OF DTC (AND ANY PAYMENT IS MADE TO CEDE & CO. OR TO SUCH OTHER ENTITY AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL INASMUCH AS THE REGISTERED OWNER HEREOF, CEDE & CO., HAS AN INTEREST HEREIN.

National Grid plc., a company incorporated under the laws of England and Wales (herein called the “Issuer”, which term includes any successor Person under the Indenture referred to hereinafter), for value received, hereby promises to pay to Cede & Co., or registered assigns, the principal sum of $[•] on January 11, 2034 and to pay interest thereon from January 11, 2024 or from the most recent Interest Payment Date to which interest has been paid or duly provided for, semi-annually in arrears on January 11 and July 11 of each year, commencing July 11, 2024 at the rate of 5.418% per annum until Maturity, and at Maturity.

Interest will be computed on the basis of a 360-day year consisting of twelve 30-day months. Except as provided below for the first Interest Payment Date, on each Interest Payment Date, the Issuer will pay interest on the Designated Securities for the period commencing on and including the immediately preceding Interest Payment Date and ending on and including the day immediately preceding that Interest Payment Date. On the first Interest Payment Date, the Issuer will pay interest for the period beginning on and including January 11, 2024 and ending on and excluding July 11, 2024. If any Interest Payment Date falls on a day that is not a Business Day, the interest payment shall be postponed to the next day that is a Business Day, and no interest on such payment shall accrue for the period from and after such Interest Payment Date. If the Maturity of the Designated Securities is not a Business Day, payment of principal and interest on the Designated Securities will be made on the next succeeding day that is a Business Day and no interest will accrue for the period from and after the Maturity.

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The interest so payable, and punctually paid or duly provided for, on any Interest Payment Date will, as provided in the Indenture, be paid to the Person in whose name the Designated Securities represented hereby (or one or more Predecessor Securities) are registered at the close of business on the Regular Record Date for such Interest Payment Date, which shall be the 15th calendar day preceding such Interest Payment Date, whether or not such day is a Business Day. Any such interest not so punctually paid or duly provided for will forthwith cease to be payable to the Holder on such Regular Record Date and may either be paid to the Person in whose name the Designated Securities represented hereby (or one or more Predecessor Securities) are registered at the close of business on a Special Record Date for the payment of such defaulted interest to be fixed by or on behalf of the Company, notice whereof shall be given to Holders of Designated Securities not less than 15 days prior to such Special Record Date, or be paid at any time in any other lawful manner not inconsistent with the requirements of any securities exchange on which the Designated Securities may be listed, and upon such notice as may be required by such exchange, all as more fully provided in the Indenture.

The Bank of New York Mellon, London Branch shall initially act as Trustee and as Paying Agent with respect to the Designated Securities.

Reference is hereby made to the further provisions of the Designated Securities set forth on the reverse of this Security Certificate, which further provisions shall for all purposes have the same effect as if set forth at this place.

Unless the certificate of authentication hereon has been executed by the Trustee referred to on the reverse hereof by manual, facsimile or electronic signature of an authorized signatory, provided that any electronic signature is a true representation of the signer’s actual signature, the Designated Securities represented by this Security Certificate shall not be entitled to any benefit under the Indenture or be valid or obligatory for any purpose.

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IN WITNESS WHEREOF, the Issuer has caused this instrument to be duly executed manually, by facsimile or electronically.

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CERTIFICATE OF AUTHENTICATION

This is one of the Security Certificates representing the Securities of the series designated therein referred to in the within-mentioned Indenture.

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REVERSE OF SECURITY CERTIFICATE

This Security Certificate is one of the Security Certificates representing a duly authorized issue of 5.418% Notes due 2034 (the “Designated Securities”), issued under an Indenture, dated as of June 12, 2023 (as amended and supplemented the “Original Indenture”), between the Issuer and The Bank of New York Mellon, London Branch, as Trustee (herein called the “Trustee”, which term includes any other successor trustee under the Indenture), as supplemented with respect to the Designated Securities by the Second Supplemental Indenture, dated as of January 11, 2024, between the Issuer and The Bank of New York Mellon, London Branch, as Trustee and Paying Agent (collectively with the Original Indenture, as supplemented, the “Indenture”) and reference is hereby made to the Indenture for a statement of the respective rights, limitations of rights, duties and immunities thereunder of the Issuer, the Trustee and the Holders of the Designated Securities and of the terms upon which each Security Certificate representing the Designated Securities is, and is to be, authenticated and delivered.

At any time and from time to time, the Issuer may redeem all or a part of the Designated Securities, upon not less than 15 nor more than 60 days’ prior notice delivered to the registered address of each Holder of Designated Securities or otherwise in accordance with the procedures of the Depository. If the Issuer elects to redeem the Designated Securities prior to October 11, 2033, the Issuer shall pay a Redemption Price, as calculated by the Issuer, equal to the greater of (1) 100% of the principal amount of the Designated Securities redeemed and (2) the present value at the applicable Redemption Date of (i) the principal amount of such Designated Securities on such Redemption Date, plus (ii) all required interest payments due on such Designated Securities through October 11, 2033, computed using a discount rate equal to the Treasury Rate determined on the second Business Day preceding the Redemption Date plus 25 basis points, less accrued and unpaid interest, plus, in each case, accrued and unpaid interest, if any, to the Redemption Date, subject to the rights of Holders of Designated Securities at the close of business on the relevant Regular Record Date to receive interest due on the relevant Interest Payment Date. If the Issuer elects to redeem the Designated Securities on or after October 11, 2033 (the date that is three months prior to the maturity date), the Company shall pay a Redemption Price equal to 100% of the principal amount of the Designated Securities to be redeemed plus accrued and unpaid interest thereon to, but not including, the Redemption Date, subject to the rights of Holders of Designated Securities at the close of business on the relevant record date to receive interest due on the relevant Interest Payment Date.

“Treasury Rate” means, as calculated by the Issuer as of any Redemption Date, the yield to maturity (computed as of the second Business Day immediately preceding that Redemption Date) of the United States Treasury securities with a constant maturity most nearly equal to the period from the Redemption Date to October 11, 2033 (three months prior to the maturity date); provided, however, that if the period from the Redemption Date to October 11, 2033 is less than one year, the weekly average yield on actually traded United States Treasury securities adjusted to a constant maturity of one year will be used.

If an Event of Default with respect to the Designated Securities shall occur and be continuing, principal of, premium, if any, and accrued but unpaid interest on the Designated Securities may be declared due and payable in the manner, with the effect and subject to the conditions provided in the Indenture.

The Indenture permits, with certain exceptions as therein provided, the amendment thereof and the modification of the rights and obligations of the Issuer and the rights of the Holders of the Securities of each series to be affected under the Indenture at any time by the Issuer and the Trustee with the consent of the Holders of a majority in principal amount of the securities at the time Outstanding of each series to be affected. The Indenture also contains provisions permitting the Holders of specified percentages in principal amount of the Designated Securities at the time Outstanding, on behalf of the Holders of the Designated Securities, to waive compliance by the Issuer with certain provisions of the Indenture and certain past defaults under the Indenture and their consequences. Any such consent or waiver by the Holder of the Designated Securities represented by this Security Certificate shall be conclusive and binding upon such Holder and upon all future Holders of the Designated Securities represented by this Security Certificate and of the Designated Securities represented by any Security Certificate issued upon the registration of transfer of the Designated Securities represented by this Security Certificate or in exchange thereof or in lieu thereof, whether or not notation of such consent or waiver is made upon this Security Certificate.

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The Indenture contains provisions for redemption of the Designated Securities at the option of the Holders following a Restructuring Event.

The Indenture contains provisions for redemption of the Designated Securities for tax purposes in whole but not in part at the option of the Issuer.

The Indenture contains provisions for the payment of Additional Amounts, payable in the manner and subject to the conditions provided in the Indenture.

No reference herein to the Indenture and no provision of the Designated Securities or of the Indenture shall alter or impair the obligation of the Issuer, which is absolute and unconditional, to pay the principal of and interest and, to the extent that payment of such interest shall be legally enforceable, interest on any overdue principal or premium on any overdue interest, on the Designated Securities at the rate or rates herein prescribed.

As provided in the Indenture, the Issuer shall cause to be kept at the Corporate Trust Office of the Trustee a Securities Register in which, subject to such reasonable regulations as it may prescribe, the Issuer shall provide for the registration of Designated Securities and of transfers of Designated Securities.

No service charge shall be made for any such registration of transfer or exchange, but the Issuer or the Trustee may require payment of a sum sufficient to cover any transfer tax or similar governmental charge payable in connection therewith other than as set forth in the Indenture.

Prior to due presentment of this Security Certificate for registration of transfer of any Security represented hereby, the Issuer, the Trustee and any agent of the Issuer or the Trustee may treat the Person in whose name such Security is registered as the owner of such Security for the purpose of receiving payment of principal of and any premium and (subject to Section 3.8 of the Original Indenture) any interest on such Security and for all other purposes whatsoever, whether or not such Security be overdue, and neither the Issuer, the Trustee nor any agent of the Issuer or the Trustee shall be affected by notice to the contrary.

Pursuant to Section 5-1401 of the General Obligations Law of the State of New York, the Indenture and the Designated Securities shall be governed by, and construed in accordance with, the laws of the State of New York.

All terms used in this Security Certificate which are not otherwise defined herein shall have the meanings assigned to them in the Indenture.

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Exhibit 5.1

		Linklaters LLP One Silk Street London EC2Y 8HQ Telephone (+44) 20 7456 2000 Facsimile (+44) 20 7456 2222 DX Box Number 10 CDE

The Directors

National Grid plc

1-3 Strand

London WC2N 5EH

11 January 2024

U.S.$750,000,000 5.418 per cent. Notes due 2034 (the “Notes”) issued by National Grid plc (the “Issuer”)

This communication is confidential and may be privileged or otherwise protected by work product immunity.

Linklaters LLP is a limited liability partnership registered in England and Wales with registered number OC326345. It is a law firm authorised and regulated by the Solicitors Regulation Authority. The term partner in relation to Linklaters LLP is used to refer to a member of Linklaters LLP or an employee or consultant of Linklaters LLP or any of its affiliated firms or entities with equivalent standing and qualifications. A list of the names of the members of Linklaters LLP together with a list of those non-members who are designated as partners and their professional qualifications is open to inspection at its registered office, One Silk Street, London EC2Y 8HQ or on www.linklaters.com and such persons are either solicitors, registered foreign lawyers or European lawyers.

Please refer to www.linklaters.com/regulation for important information on Linklaters LLP’s regulatory position.

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SCHEDULE

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Exhibit 5.2

		Linklaters LLP 1290 Avenue of the Americas New York, NY 10104 Telephone (+1) 212 903 9000 Facsimile (+1) 212 903 9100

National Grid plc

1-3 Strand

London WC2N 5EH

England

January 11, 2024

Ladies and Gentlemen,

Issue by National Grid plc (the “Issuer”) of U.S.$750,000,000 5.418% Notes due 2034 (the “Debt Securities”)

We have acted as United States counsel to the Issuer in connection with the issuance of the Debt Securities by the Issuer. The Debt Securities are being issued pursuant to the Indenture dated as of June 12, 2023, as amended and supplemented from time to time (the “Base Indenture”), as supplemented by a second supplemental indenture dated as of January 11, 2024 (the “Second Supplemental Indenture”, and together with the Base Indenture, the “Indenture”) between the Issuer and The Bank of New York Mellon, London Branch, as trustee (the “Trustee”).

This opinion is limited to the federal law of the United States and the laws of the State of New York, and we express no opinion as to the effect of the laws of any other State of the United States or any other jurisdiction.

For the purpose of this opinion, we have examined the Indenture, such certificates and other documents, and such questions of law, as we have considered necessary or appropriate. We have assumed that the Issuer has the power to execute and deliver the Debt Securities and the Indenture, and perform its obligations thereunder, that the Indenture has been duly and validly authorized, executed and delivered under the laws of England and Wales by the Issuer, that the Debt Securities have been duly and validly authorized and delivered under the laws of England and Wales by the Issuer, that the Debt Securities conform to the form examined by us and that the signatures on all documents examined by us are genuine, assumptions that we have not independently verified.

In our opinion, the Debt Securities have been duly executed, authenticated, issued and delivered and constitute valid and legally binding obligations of the Issuer, enforceable in accordance with their terms, subject to bankruptcy, insolvency, fraudulent transfer, reorganization, moratorium and similar laws of general applicability relating to or affecting creditors’ rights and to general equity principles.

This communication is confidential and may be privileged or otherwise protected by work product immunity.

Linklaters LLP is a multinational limited liability partnership registered in England and Wales with registered number OC326345 including solicitors of the Senior Courts of England and Wales, members of the New York and District of Columbia Bars and foreign legal consultants in New York. It is a law firm authorised and regulated by the Solicitors Regulation Authority. The term partner in relation to Linklaters LLP is used to refer to a member of Linklaters LLP or an employee or consultant of Linklaters LLP or any of its affiliated firms or entities with equivalent standing and qualifications. A list of the names of the members of Linklaters LLP together with a list of those non-members who are designated as partners and their professional qualifications is open to inspection at its registered office, One Silk Street, London EC2Y 8HQ, England or on www.linklaters.com.

Please refer to www.linklaters.com/regulation for important information on Linklaters LLP’s regulatory position.

We hereby consent to the filing of this opinion as an exhibit to a report on Form 6-K to be submitted by the Issuer on the date hereof. In giving such consent, we do not thereby admit that we are in the category of persons whose consent is required under Section 7 of the Securities Act.

Very truly yours,

/s/ Linklaters LLP

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