Exhibit 10.1

  

   

    

  
    AMENDMENT NO. 1 TO WARRANT AGREEMENT

     

    This Amendment (this “Amendment”) is
      made as of December 17, 2021, by and between BTRS Holdings Inc., a Delaware corporation (the “Company”) (f/k/a South Mountain Merger Corp. (“South Mountain”)), and Continental Stock Transfer & Trust Company, a New York corporation, as warrant agent (the “Warrant Agent”),



      and constitutes an amendment to that certain Warrant Agreement, dated as of June 19, 2019 (the “Existing Warrant Agreement”), between South Mountain Merger Corp. (“South Mountain”) and the Warrant Agent. Capitalized terms used but not otherwise defined in this Amendment shall have the meanings given to such terms in the Existing Warrant
      Agreement.

     

    WHEREAS, on January 12, 2021, the Company consummated the mergers pursuant to that certain Business Combination
      Agreement, dated October 18, 2020 (as amended on December 13, 2020), by and among South Mountain, BT Merger Sub I, Inc., a Delaware corporation and a wholly owned subsidiary of South Mountain, BT Merger Sub II, LLC, a Delaware limited liability
      company and a wholly owned subsidiary of South Mountain, and Factor Systems, Inc. (d/b/a Billtrust), a Delaware corporation (the “South Mountain Business Combination”), and
      in connection therewith the Company was renamed BTRS Holdings Inc.;

     

    WHEREAS, in accordance with Section 4.4 of the Existing Warrant Agreement, upon effectiveness of the South
      Mountain Business Combination, the holders of the Warrants thereafter had the right to purchase and receive, upon the basis and upon the terms and conditions specified in the Warrants and in lieu of the shares of the Class A common stock of South
      Mountain immediately theretofore purchasable and receivable upon the exercise of the rights represented thereby, an Alternative Issuance in shares of Class 1 common stock, par value $0.0001, per share, of the Company (the “Common Stock”);

     

    WHEREAS, Section 9.9 of the Existing Warrant Agreement provides that the Company and the Warrant Agent may amend,
      subject to certain conditions provided therein, the Existing Warrant Agreement with the vote or written consent of the Registered Holders of 50% of the number of the then outstanding Public Warrants;

     

    WHEREAS, the Company desires to amend the Existing Warrant Agreement to provide the Company with the right to
      require the holders of the Warrants to exchange all of the outstanding Warrants for shares of Common Stock, on the terms and subject to the conditions set forth herein; and

     

    WHEREAS, in the exchange offer and consent solicitation undertaken by the Company pursuant to the Registration
      Statement on Form S-4 filed with the U.S. Securities and Exchange Commission, the Registered Holders of more than 50% of the then outstanding Public Warrants consented to and approved this Amendment.

     

    NOW, THEREFORE, in consideration of the mutual agreements contained herein and other good and valuable
      consideration, the receipt and sufficiency of which are hereby acknowledged, and intending to be legally bound hereby, the parties hereto agree to amend the Existing Warrant Agreement as set forth herein.

     

    1.      Amendment of Existing Warrant Agreement. The Existing
      Warrant Agreement is hereby amended by adding:

     

    (a)     the new Section 6A thereto:

     

    “6A Mandatory Exchange.

     

    6A.1 Company Election to Exchange. Notwithstanding any other provision in this Agreement to the contrary, all (and not less than all) of the outstanding Warrants may be exchanged, at the option of the Company, at any time while they are
        exercisable and prior to their expiration, at the office of the Warrant Agent, upon notice to the Registered Holders of the then outstanding Warrants, as described in Section 6A.2 below, for Common Stock (or any Alternative Issuance pursuant to
        Section 4.4), at the exchange rate of 0.27 shares of Common Stock (or any Alternative Issuance pursuant to Section 4.4) for each Warrant held by the holder thereof (the “Consideration”)


        (subject to equitable adjustment by the Company in the event of any stock splits, stock dividends, recapitalizations or similar transaction with respect to the Common Stock). In lieu of issuing fractional shares, any holder of Warrants who would
        otherwise have been entitled to receive fractional shares as Consideration will, after aggregating all such fractional shares of such holder, be paid in cash (without interest) in an amount equal to such fractional part of a share multiplied by
        $7.54.

    

    

    
      
        


    

    6A.2 Date Fixed for, and Notice of, Exchange. In the event that the Company elects to
      exchange all of the Warrants, the Company shall fix a date for the exchange (the “Exchange Date”). Notice of exchange shall be mailed by first class mail, postage prepaid,
      by the Company not less than fifteen (15) days prior to the Exchange Date to the Registered Holders at their last addresses as they shall appear on the registration books. Any notice mailed in the manner herein provided shall be conclusively presumed
      to have been duly given whether or not the registered holder received such notice. The Company will make a public announcement of its election following the mailing of such notice.

     

    6A.3 Exercise After Notice of Exchange. The Warrants may be exercised, for cash (or on
      a “cashless basis” in accordance with subsection 3.3.1(b) of this Agreement, with an adjustment to the definition of “Fair Market Value” to substitute the date on which the notice of exchange is sent for
      the date on which the nature of redemption is sent) at any time after notice of exchange shall have been given by the Company pursuant to Section 6A.2 hereof and prior to the Exchange Date. On and after
      the Exchange Date, the Registered Holder of the Warrants shall have no further rights except to receive, upon surrender of the Warrants, the Consideration.”

     

    2.      Miscellaneous Provisions.

     

    2.1    Severability. This Amendment shall be deemed severable, and
      the invalidity or unenforceability of any term or provision hereof shall not affect the validity or enforceability of this Amendment or of any other term or provision hereof. Furthermore, in lieu of any such invalid or unenforceable term or
      provision, the parties hereto intend that there shall be added as a part of this Amendment a provision as similar in terms to such invalid or unenforceable provision as may be possible and be valid and enforceable.

     

    2.2    Applicable Law. The validity, interpretation, and performance
      of this Amendment and of the Warrants shall be governed in all respects by the laws of the State of New York, without giving effect to conflicts of law principles that would result in the application of the substantive laws of another jurisdiction.
      The Company hereby agrees that any action, proceeding or claim against it arising out of or relating in any way to this Amendment shall be brought and enforced in the courts of the City of New York, County of New York, State of New York or the United
      States District Court for the Southern District of New York, and irrevocably submits to such jurisdiction, which jurisdiction shall be exclusive. The Company hereby waives any objection to such exclusive jurisdiction and that such courts represent an
      inconvenient forum.

     

    2.3    Counterparts. This Amendment may be executed in any number of
      counterparts (which may include counterparts delivered by any standard form of telecommunication) and each of such counterparts shall for all purposes be deemed to be an original, and all such counterparts shall together constitute but one and the
      same instrument. The words “execution,” “signed,” “signature,” and words of like import in this Amendment or in any other certificate, agreement or document related to this Amendment, if any, shall include images of manually executed signatures
      transmitted by facsimile or other electronic format (including, without limitation, “pdf,” “tif” or “jpg”) and other electronic signatures (including, without limitation, DocuSign and AdobeSign). The use of electronic signatures and electronic
      records (including, without limitation, any contract or other record created, generated, sent, communicated, received, or stored by electronic means) shall be of the same legal effect, validity and enforceability as a manually executed signature or
      use of a paper-based record-keeping system to the fullest extent permitted by applicable law, including the Federal Electronic Signatures in Global and National Commerce Act, the New York State Electronic Signatures and Records Act and any other
      applicable law, including, without limitation, any state law based on the Uniform Electronic Transactions Act or the Uniform Commercial Code.

     

    

    
      
        


    

    2.4    Effect of Headings. The section headings herein are for
      convenience only and are not part of this Amendment and shall not affect the interpretation thereof.

     

    2.5    Entire Agreement. The Existing Warrant Agreement, as modified
      by this Amendment, constitutes the entire understanding of the parties and supersedes all prior agreements, understandings, arrangements, promises and commitments, whether written or oral, express or implied, relating to the subject matter hereof,
      and all such prior agreements, understandings, arrangements, promises and commitments are hereby canceled and terminated.

     

    [Signature Pages Follow]

     

    

    
      
        


    

    IN WITNESS WHEREOF, each of the parties has caused this Amendment to be duly executed as of the date first above
      written.

     

    	 	
            BTRS HOLDINGS INC.

          
	 	 
	 	
            By:

          	 	
            /s/ Mark Shifke

          
	 	 	 	
            Name:          Mark
                  Shifke

          
	 	 	 	
            Title:          Chief
                  Financial Officer

          


    

    

    	 	
            CONTINENTAL STOCK TRANSFER &

            TRUST COMPANY, as Warrant Agent

          
	 	 
	 	
            By:

          	 	
            /s/ Stacy Aqui

          
	 	 	 	
            Name:          Stacy
                  Aqui

          
	 	 	 	
            Title:          Vice
                  President