For an instalment payments business choosing where to build globally, the UK makes the case on two fronts.

The first is that it’s one of the most fintech-friendly markets in the world. The regulator has built a proper framework for instalment payments rather than leaving the category in limbo. Government programmes actively back fintech businesses establishing themselves here. And the payment rails a global model depends on – card networks, open banking, near-universal acceptance – already run at scale. A new entrant spends its time solving the actual problem, not building basic plumbing.

The second is the size of the problem waiting to be solved. The UK holds one of the largest pools of untapped consumer credit anywhere: tens of millions of credit cards carrying enormous unused limits, held by people who want more flexibility in how they repay, not necessarily another credit product. That’s a market that solved credit access and usability decades ago, and never quite solved the repayment problem.

A sophisticated market, built for a credit product that hasn’t caught up

On paper, the UK is a market already well served by credit so, generally speaking, credit access isn’t the primary issue. Look closer and a different problem appears. UK cardholders are carrying over £70bn in interest-bearing balances while roughly £250bn in available credit sits untouched, across more than 55 million cards.

That’s the gap worth paying attention to: not trying to issue more credit but enabling people to repay their existing credit in a way that makes sense in 2026. Giving someone the ability to spread a purchase over time, using a limit they already qualify for, rather than pushing them toward a new loan every time they want flexibility at checkout. These shoppers don’t need more credit. They need more time. That structural mismatch turns out to matter more in a sophisticated card market than in one still building out card penetration in the first place.

Why a mature market is the harder, more useful test

The counterargument is that a fast-growing, underserved market looks attractive on paper: less competition, quicker uptake, a clearer runway. But those same conditions make it a weaker proving ground. A model that only has to work where there’s little else competing for a shopper’s attention hasn’t really been tested against the standard it will eventually need to meet everywhere. A market with a wide range of established payment methods already competing at checkout is a harder bar to clear, and clearing it says considerably more about how well a model is received in a new market.

Regulation is another factor to consider. Clearer standards raise shopper trust in instalment payments generally, and any model built on transparent, already-regulated credit infrastructure benefits as the market around it matures.

The next evolution of checkout finance

Step back from any one market, and there’s a broader shift happening in checkout finance. For years, the assumption behind flexible payments was that flexibility required something new: a new loan, a new account, a new app on a shopper’s phone. Card-linked instalments are a different answer to the same question – giving shoppers more time to repay a purchase against a credit facility they already hold, without asking them to open anything new at all.

That’s a different starting point, and it’s where I think checkout financing is heading more broadly: toward giving people better tools to manage the credit they already have, rather than issuing them more of it. There will always be a need for new lines of credit, and an endless supply of providers that are trying to issue it. But what goes under the radar is that people don’t always want to have to go that route just to get flexibility.

Why the UK is where this gets tested

The UK asks more of any fintech business than almost any market on earth: a crowded checkout, real regulatory standards, and shoppers with no shortage of ways to pay and borrow. That’s exactly why it’s worth it. A model that earns its place here has been tested against the highest bar there is, and everything it learns transfers to any market running on the same card rails.

The UK is one of the largest credit card markets in the world, and the problem at the heart of it is still unsolved: everyone at checkout is competing to issue shoppers new credit, and almost no one is helping them use the credit they already have. The hardest market and the most open one, at the same time.

That’s why I’d treat the UK as a starting point, not a later chapter. Prove that giving people more time on the credit they already have works in the world’s most competitive card market, and you haven’t just entered a new country, you’ve proven your model is built to travel.

Alex Forsyth-Thompson, Founder & CEO of Float