A class action lawsuit filed with London's Competition Appeal Tribunal takes issue with Apple's customary App Store commission rates, arguing the developer fee is passed on to consumers. In a press release Tuesday, claimants in the case argue Apple has overcharged nearly 20 million UK App Store customers for years by imposing an "excessive" and "unlawful" 30% cut of in-app purchases on developers. The group is seeking damages of up to 1.5 billion pounds, reports the BBC. As noted by the publication, the UK's class action legal structure differs from U.S. proceedings, though "optout" claims have been accepted since 2015. If approved by the tribunal, the action would cover any UK users who purchased paid apps, subscriptions or in-app purchases on an iPhone or iPad since October 2015.