For all the talk of challenger banks in Europe, Southeast Asia, and the U.K., the movement to bring alternative banking options to consumers and small businesses in the U.S. may deserve more attention than it tends to get. And this week’s news that SME-based challenger bank NorthOne has raised $21 in Series A funding, is a reminder of why.

“We created NorthOne to serve businesses that are often underserved by big banks,” bank CEO Eytan Bensoussan explained. “Having grown up in a family of small business owners myself, I know first-hand what to expect when it comes to small business banking.”

The round was led by Battery Ventures’ Shiran Shalev, and featured participation from Redpoint Ventures and Tom Williams. The investment takes the bank’s total capital to more than $23 million.

“With this funding,” Bensoussan added, “NorthOne will be able to continue to develop solutions that simplify the most painful part of managing a small business, its finances.” The additional capital will also enable the challenger bank to add to its product and engineering teams, as well as spend more on marketing and customer acquisition.

NorthOne offers small and medium-sized businesses a digital, FDIC-insured, business checking account with mobile ACH, wires, check deposits, and access to 300,000 fee-free ATMs across the U.S. NorthOne’s mobile-first, API-enabled platform also offers overseas vendor payments, and software integration with expense management, accounting, and e-commerce systems. The company noted that, in the second half of last year, it has signed up 1% of all small businesses that applied for bank accounts in the U.S.

“Millions of dollars are spent using NorthOne debit cards every month,” Bensoussan wrote on the company’s blog today. “And we expect those numbers to keep rising as we open thousands upon thousands of new NorthOne bank accounts each month.”

Founded in 2016, NorthOne launched its small business banking account last fall, in partnership with Radius Bank.