Why Open Banking Is Eating Card Payments in the UK (And the Numbers Prove It)

I've been building payment infrastructure for the last few years. Cards were the default. Visa, Mastercard, Stripe — the holy trinity of "just make it work." Then I looked at the numbers. 53% growth in open banking payments year-on-year. 351 million payments in 2025 alone. 33.1 million users expected by 2026 — that's over 60% of UK adults. And account-to-account payments are projected to grow at 13.63% CAGR through 2031 — the fastest of any payment method in the UK. Meanwhile, card transaction growth has flatlined. Debit cards still hold about 42% of the UK market, but merchants are quietly migrating away. The reason isn't complicated. It's the fees. The Tax You Don't See Here's what actually happens when a customer taps their card at your checkout: Interchange fee → goes to the card-issuing bank (0.2–0.3% for UK debit, 0.3% for credit) Scheme fee → goes to Visa or Mastercard (0.02–0.15% plus per-transaction) Acquirer fee → goes to your payment processor Gateway fee → goes to your paym