Startup Causa Prima raises $20 million to tackle billing disputes with AI agents

Causa Prima is trying to give AI agents a job most software still leaves to humans: arguing over bills. The Delaware startup said Tuesday that it closed a $20 million seed round in September to grow its agent-to-agent platform, which helps companies and their suppliers settle payment disputes and get invoices paid faster.

The company is built around a simple complaint: a lot of billing work is still manual. Instead of making a single business more efficient in isolation, Causa Prima wants agents to work across company boundaries, handling the back-and-forth between accounts payable and accounts receivable. Base10 Partners led the round, with QED Investors, FJ Labs, Creandum, Kfund, and Borusan Ventures also taking part. Causa Prima did not disclose its valuation.

The numbers behind the problem are big. Fortune Business Insights puts business-to-business payments at roughly $98 trillion a year. Mastercard estimates the wider market opportunity at $125 trillion. And the delay is real: a 2025 Ardent Partners report found that nearly half of accounts payable executives say slow invoice approvals are their biggest challenge, with processing taking more than eight days on average.

Causa Prima is already a real company, not just a demo. It has 25 employees split between Madrid and Munich, and the new money is meant to support a New York office as it moves into the U.S. The startup makes money by taking a cut when its agents successfully negotiate early payments between buyers and suppliers.

The founders know this corner of finance well. Maex Ament worked at SAP and later built Taulia before founding Centrifuge. Henrik Gebbing moved from McKinsey to cofound Finoa. The pair met in Madrid nearly a decade ago, kept in touch, and last year turned a friendship into a plan for the agentic AI wave. Philip Stanislaus, who had led engineering under Ament at Centrifuge, joined as CTO. The company’s name comes from the Latin for “first cause,” which is Ament’s way of saying getting paid is the point of business.