BTRS Holdings Inc. (Nasdaq: BTRS) is the combined public company formed through the de-SPAC merger of South Mountain Merger Corp, a blank-check vehicle sponsored by South Mountain Equity Partners, with Billtrust, a business-to-business payment automation and accounts-receivable software provider. South Mountain Merger Corp completed its SPAC IPO in 2020, targeting the financial technology sector with a focus on B2B order-to-cash and integrated payments solutions. The transaction closed in January 2021, and BTRS Holdings subsequently filed an S-1 registration statement with the SEC on February 3, 2021. The company operates in the B2B fintech space, serving enterprise clients with cloud-based payment cycle management. Sign up for full data on SpacDesk to access comprehensive filings, deal timelines, and analytics on BTRS and hundreds of other SPAC transactions.