Harcus Parker and Hausfeld seek to bring an opt-out claim covering 1m UK businesses, the latest in a run of UK legal and regulatory action on card fees.
Visa and Mastercard are facing a proposed £5bn ($6.66bn) collective claim at the Competition Appeal Tribunal (CAT) regarding the interchange fees British businesses have paid on card transactions since October 2020.
As reported by The Guardian, law firms Harcus Parker and Hausfeld have filed an application with the tribunal to bring this collective action centring on so-called ‘multilateral interchange fees’ (MIFs).
These are set by the two card networks and paid by merchants – via their banks – on every card transaction. According to the claim, a lack of competition has allowed the networks to keep fees for debit, credit, and prepaid cards higher than they otherwise would have been. The claim covers fees incurred over a six-year period, plus interest.
Those involved in the case estimate its value at approximately £5bn, based on the number of businesses they allege have been overcharged between 2020 and 2026.
If the CAT certifies the case, an estimated 1 million British businesses, charities and other organisations with a turnover of less than £100m will be automatically included in the proceedings, unless they explicitly choose to opt out.
For individual parties, the amounts involved could reach several thousand pounds. Larger companies, which are required to actively sign up (‘opt-in’), could potentially claim sums running into the tens of millions of pounds for the period in question.
Stephen Allen, a former travel industry executive who has initiated several collective lawsuits against the two networks since 2021, is leading this claim, with funding provided by Bench Walk Advisors, a firm that has been active in litigation financing since 2017.
Visa, Mastercard reject the claim
Mastercard said it disagreed with the basis of the case and described it as part of a “growing trend of opportunistic funder-backed litigation”. The company argues interchange fees support the UK’s payment ecosystem by enabling consumers and businesses to make and receive payments quickly and securely.
Mastercard further contends this type of litigation is what the UK government aims to curb through proposed reforms to the ‘opt-out’ system for collective actions – plans that were put forward for consultation in the summer.
Visa maintains it still considers interchange fees to be essential for a secure digital payment system, which benefits consumers, merchants, and banks alike.
Visa, Mastercard rulings and regulatory action in the UK
On October 8, Ann Pope – a former Senior Director at the UK’s Competition and Markets Authority (CMA) – announced a collective damages claim (an “opt-out” claim) valued at £700m on behalf of approximately 126,000 British businesses.
Her case concerns fees charged for online payments made by customers using cards issued within the European Economic Area (EEA). According to Pope, these fees have increased fivefold since Brexit.
In December 2024, the Payment Systems Regulator (PSR) launched a consultation regarding a cap on cross-border “interchange” fees. This followed findings rates between the UK and the EEA had risen from 0.2% to 1.15% for consumer debit cards, and from 0.3% to 1.5% for credit cards – an increase costing British businesses an estimated £150m-£200m annually.
In January 2026, the High Court dismissed a legal challenge brought by Visa, Mastercard, and Revolut against the regulator’s authority. Furthermore, the PSR concluded that, between 2017 and 2023, the card networks had raised their base and processing fees by more than 25%, driving up costs for UK businesses by at least £170m per year.
In June 2025, the CAT ruled in an umbrella proceeding – brought by more than 2,000 merchants – the ‘interchange’ fees (MIFs) applied by card networks were in violation of competition law.
According to the claimants’ lawyers, this marked the first time it had been determined fees for business cards and interregional transactions contravene competition law. In March 2026, the Court of Appeal granted Visa and Mastercard permission to appeal this judgment on all grounds.
Legal proceedings in the US
In December 2025, Visa and Mastercard agreed to pay a combined $167.5m to settle a US class-action lawsuit – filed in 2011 – which alleged that they kept ATM access fees artificially high.
In June, a federal court in Brooklyn granted preliminary approval for a revised $38bn settlement with approximately 12 million merchants, concerning a legal dispute over interchange fees dating back to 2005.
According to the Merchants Payments Coalition, nearly 1,000 businesses and trade associations have since petitioned the court to reject this settlement.
