- London fintech Primer raises an oversubscribed $100m Series C led by Sofina, totalling $170m in funding.
- Funds will expand AI agent Primer Companion and drive US growth.
- US revenue, currently one-fifth of the total, is targeted to exceed one-third by 2028.
Primer, the London-based payments infrastructure company, has closed a $100 million Series C funding round, taking its total capital raised to $170 million. The round was oversubscribed and led by Sofina, the Belgian investment group, with Peak XV Partners joining alongside a roster of returning backers: Balderton, Accel, ICONIQ, Tencent, and Speedinvest.
The company, founded in 2020 by Gabriel Le Roux and Paul Anthony, both alumni of Braintree, the Chicago-based payments gateway that PayPal acquired in 2013 has built what it describes as a unified infrastructure layer for global enterprise payments. Its platform sits across the full transaction lifecycle, from checkout to payout, consolidating the fragmented web of processors, acquirers, fraud tools and payment methods that large merchants typically rely on.
“In the next few years, every payment decision in a large business will be initiated, optimised or audited by AI. That shift is already underway,” said Gabriel Le Roux, co-founder and CEO, Primer.
The intelligent layer
At the heart of the fundraise is Primer’s bet that payments is becoming an AI problem as much as a plumbing one. The company’s platform captures more than 400 data points per transaction and manages nearly 100% of customer payment volume for its clients.
“Payments is super complex,” Le Roux has said previously, and the figures bear that out: a single large e-commerce merchant might route transactions across Stripe, Adyen, Braintree and a local banking partner simultaneously, with each integration creating its own siloed data trail and its own surface area for errors.
Primer’s answer is Primer Companion, an AI agent launched in November 2025 that the company is now building out to act autonomously on behalf of merchants — running experiments, optimising approval rates, flagging anomalies — within parameters set by the merchant.
“We don’t want merchants chasing problems or missing opportunities,” Le Roux said. “With full context across every payment, Primer Companion can act on their behalf, knowing what’s happening, why, and what to do next.”
The company already processes billions of transactions annually for brands including GetYourGuide, Dialpad, Rail Europe, Printful and Lime. It positions itself not as a competitor to Stripe, Adyen or Checkout.com, all of which focus primarily on processing but as an orchestration layer that sits above them, routing intelligently across providers and giving merchants visibility they would otherwise lack.
The American push
The US is the strategic centrepiece of the new capital deployment. The market currently accounts for roughly one-fifth of Primer’s total revenue, with annual recurring revenue in the region doubling year-on-year. The company is targeting growth to more than a third of overall revenue from the US by 2028, and plans to hire up to 50 people there to support the expansion.
“The US is the world’s largest payments market and the clearest expression of the problem Primer was built to solve,” the company said in its announcement.
“Gabriel and the team have spent the past six years building the platform best suited to that future, earning the trust of some of the world’s most demanding merchants,” adds Jean-François Burguet, Head of Digital, Sofina.
Investor confidence
For Sofina, the lead, the investment reflects a broader thesis that the payments industry is approaching a structural turning point as merchants consolidate onto unified infrastructure and AI becomes central to transaction decision-making.
Aakash Kapoor, a principal at Peak XV Partners, said Primer’s depth of data context was the defining factor. “Primer has built a unified infrastructure that manages nearly 100% of payment volume for its clients, giving global enterprises a complete view across multiple processors, acquirers, fraud tools and payment methods,” he said. “As payments enter a new architectural era, that depth of context becomes critical for AI agents to make decisions.”
The oversubscribed nature of the round — meaning investor demand exceeded the $100 million the company sought to raise — suggests that conviction extends well beyond Primer’s existing backers, and that the market for payments infrastructure capable of supporting AI workloads remains intensely competitive for capital.
