MasterCard faces a £14 billion claim in the second action filed under the new Consumer Rights Act 2015. This Act, which came into force on 1 October 2015, broadened the jurisdiction of the Competition Appeal Tribunal enabling collective actions to be brought on an "opt-out" basis on behalf of consumers who have suffered loss.

In 2014, the European Commission concluded a 10 year long legal battle against MasterCard finding that it had infringed EU law by imposing excessive, anti-competitive card charges (known as "interchange" fees) on the use of its debit and credit cards over a 16 year period between 1992 and 2008. These charges were incurred by retailers and then passed on to consumers through increased prices.

Anti-competitive claims have been brought by retailers affected by MasterCard's charges. The first successful stand-alone damages action in the UK concluded in July 2016, when Sainsbury's successfully established that MasterCard had infringed competition law and demonstrated that it had suffered loss as a result of the infringement. It was awarded £68.5m (plus interest) by the Competition Appeal Tribunal and it is expected that this decision will pave the way for similar claims against MasterCard by affected retailers.

Certainly, it is well-timed for the collective action now being progressed by US law firm, Quinn Emanuel Urquhart & Sullivan, on behalf of consumers. The claim is led by consumer representative, Walter Merricks CBE, the former Chief Financial Services Ombudsman, who has said that his aim is to "get the redress to which UK consumers are entitled and to ensure that MasterCard cannot hold on to the illegal profits it made." As the European Commission has already established that MasterCard's fees were illegal, the consumers need only show that they have suffered loss as a consequence of this illegality (i.e. it is a "follow-on" claim).

Under the Consumer Rights Act, all UK consumers who have suffered loss will automatically become part of the group of claimants unless they expressly opt-out. This means that no action will be required by consumers, as they will automatically be eligible to receive compensation at the conclusion of the claim.

The collective action is being financed by Chicago-based litigation funder, Gerchen Keller Capital LLC. Gerchen, said to be the world's largest litigation funder, is providing up to £40 million towards the litigation costs in what will be the firm's largest non-US litigation and the largest legal claim in British history.