UK businesses seek about £5bn from Visa and Mastercard over card fees charged since October 2020

A new group of law firms wants to take Visa and Mastercard to the UK Competition Appeal Tribunal on behalf of businesses that accepted card payments. The application, first reported on 26 October 2026, asks the tribunal for permission to bring collective proceedings. It argues that merchants were overcharged through multilateral interchange fees on debit, credit and prepaid card transactions from October 2020 onwards. The claim is put at about £5bn plus interest and is backed by the litigation funder Bench Walk Advisors. The proposed structure has two tiers. An estimated one million UK businesses, organisations and charities with turnover below £100m would be included automatically unless they opt out. Larger merchants would have to opt in, and the reports suggest that the biggest of them could each be owed tens of millions. The proposed lead claimant is a former travel executive who has pursued the two networks in several earlier group actions since 2021. Nothing has been decided yet. The tribunal must first rule on whether the case can proceed as collective proceedings, which typically takes months. Mastercard called the application speculative and said it strongly disagrees with its basis. Visa said interchange is an essential part of a secure payments system. For online merchants the case matters because it covers the period after the UK left the EU, when cross-border interchange on payments between UK merchants and EEA cardholders rose sharply. Any recovery would depend on proof of card acceptance and fees paid, so the records merchants keep today could decide what they are able to claim later.