Mastercard and Visa are facing new collective legal claims potentially worth £5 billion over interchange fees charged on card transactions, adding to a growing number of competition cases before the Competition Appeal Tribunal (CAT).
The claims have been filed by proposed class representative Stephen Allen, the former head of Portman Travel. Law firms Harcus Parker and Hausfeld are acting in the proceedings, which concern multilateral interchange fees (MIFs) set by Mastercard and Visa.
These fees are paid by businesses indirectly through their banks whenever customers make card payments. They are estimated to account for a substantial proportion of the merchant service charges businesses pay to accept card transactions.
The proposed claims could cover UK businesses of different sizes, from small independent retailers to large national companies, that accept consumer debit, credit and prepaid cards issued through Mastercard and Visa. If the claims proceed, eligible businesses may have an opportunity to seek compensation for alleged overcharges.
Allen said that businesses accepting card payments bear the cost of these fees and argued that the claims could provide an opportunity to recover losses. He referred to earlier competition proceedings concerning interchange fees and said businesses, rather than consumers, had borne much of the financial impact.
The new proceedings follow other significant claims before the tribunal. Earlier this month, a separate £700 million collective claim was brought on behalf of a proposed group of approximately 126,000 UK businesses. Another claim involving companies within the Mastercard and Visa groups was also registered with the CAT last month.
The litigation follows the landmark Merricks v Mastercard proceedings, which concluded in 2024 with a £200 million settlement. That case became a significant development in the UK’s collective competition claims system.
A case management hearing concerning the wider interchange fee proceedings has also taken place before the tribunal. Further procedural steps will determine how the claims progress.
Mastercard has strongly disputed the basis of the latest claims. A company spokesperson said interchange fees play an important role in supporting the UK payments system and enabling secure, efficient transactions for businesses and consumers.
The spokesperson also described the claim as speculative and criticised the growth of litigation backed by external funders. Mastercard argued that the proposed government reforms to opt-out collective actions were intended to address concerns of this kind.
The case adds to continuing debate about the balance between allowing businesses to seek compensation for alleged competition law breaches and preventing claims that defendants consider unjustified. The outcome and progress of the proceedings may have implications for businesses that accept card payments and for the future development of collective competition litigation in the UK.
