As previously announced, the board of directors of BTRS Holdings Inc. (the “Company”) informed Marcum LLP, the Company’s independent
registered public accounting firm prior to the transactions contemplated by that certain Business Combination Agreement dated October 18, 2020 (the “Transactions”), that Marcum LLP will be dismissed effective following the completion of our audit
for the year ended December 31, 2020, which consists only of the pre-Transactions accounts of BTRS Holdings Inc. (f/k/a South Mountain Merger Corp.).
On March 24, 2021, when we filed our Annual Report on Form 10-K with the Securities and Exchange Comission (the "SEC"), Marcum LLP
completed its audit of the consolidated financial statements as of December 31, 2020 and 2019, for the year ended December 31, 2020 and for the period February 28, 2019 (inception) through December 31, 2019 of BTRS Holdings Inc. (f/k/a South
Mountain Merger Corp.). Marcum LLP was dismissed as our independent registered public accounting firm on March 24, 2021.
Marcum LLP’s report on the consolidated financial statements as of December 31, 2020 and 2019, for the year ended December 31, 2020 and
for the period February 28, 2019 (inception) through December 31, 2019 of BTRS Holdings Inc. (f/k/a South Mountain Merger Corp.) did not contain any adverse opinion or disclaimer of opinion, and were not qualified or modified as to uncertainties,
audit scope, or accounting principles.
During the fiscal periods ended December 31, 2020 and 2019, and the subsequent interim period through March 24, 2021, the effective
date of Marcum LLP’s dismissal, there were: (i) no disagreements within the meaning of Item 304(a)(1)(iv) of Regulation S-K and the related instructions between the Company and Marcum LLP on any matters of accounting principles or practices,
financial statement disclosure, or auditing scope or procedure which, if not resolved to Marcum LLP’s satisfaction, would have caused Marcum LLP to make reference thereto in its reports; and (ii) no “reportable events” within the meaning of Item
304(a)(1)(v) of Regulation S-K.
On January 12, 2021,
the Board approved the engagement of BDO USA, LLP (“BDO”) as the Company's independent registered public accounting firm to audit the Company’s consolidated financial statements for the year ending December 31, 2021. BDO served as the
independent registered public accounting firm of Factor Systems, Inc. (d/b/a Billtrust) prior to the Transactions. During the period from February 28, 2019 (inception) through December 31, 2020, and the subsequent interim period preceding the
engagement of BDO, and through the date of this Current Report on Form 8-K (this “Report”), neither the Company nor anyone on its behalf has previously consulted with BDO regarding either: (i) the application of accounting principles to a
specified transaction, either completed or proposed; or the type of audit opinion that might be rendered on the Company’s consolidated financial statements, and neither a written report nor oral advice was provided to the Company that BDO
concluded was an important factor considered by the Company in reaching a decision as to the accounting, auditing or financial reporting issue; or (ii) any matter that was either the subject of a “disagreement” or a “reportable event” (as
described in Items 304(a)(1)(iv) and 304(a)(1)(v) of Regulation S-K, respectively).
We have requested that Marcum LLP furnish a letter addressed to the SEC stating whether it agrees with the above statements. A copy of
Marcum LLP’s letter, dated March 30, 2021, is attached hereto as Exhibit 16.1.