Visa and Mastercard are being threatened with a potential £5bn lawsuit for allegedly stifling competition and charging UK businesses excessive fees.

The law firms Harcus Parker and Hausfeld have lodged an application at the Competition Appeal Tribunal in hopes of pursuing a group claim that would compensate companies who, they claim, have been overcharged on customer card payments since October 2020.

The claim will centre on multilateral interchange fees, which are set by Visa and Mastercard and then paid by businesses through their banks every time a customer pays by card. The argument is that the lack of competition has left businesses at their mercy – and paying higher fees on debit, credit and prepaid cards – as a result.

The case will hope to claw back fees charged over the past six years, as well as interest on those losses.…