Apple is facing a £2 billion ($2.7 billion) lawsuit at London’s Competition Appeal Tribunal brought on behalf of thousands of app developers over its App Tracking Transparency feature, launched in April 2021. The claim alleges Apple abused its market position by holding third-party apps to stricter tracking requirements across apps and websites while imposing lighter obligations on its own advertising and data-collection operations, tilting the playing field in favor of Apple’s advertising ecosystem and eroding revenue and user-growth economics for App Store developers. Ann Pope, a former senior director for antitrust at the U.K.’s Competition and Markets Authority and director of ATT Collective Action Limited, is leading the case. She said the policy resulted in very significant harm to businesses that depend on Apple as a gatekeeper and that the action aims to protect British businesses, ensure Apple’s rules are fair, and compensate losses they have suffered. Pope has also warned that privacy protections cannot become a reason for digital platforms to apply one set of rules to themselves and another to developers. Apple said App Tracking Transparency was created to give users a simple way to control whether apps may track their activity and that it is bound by the exact same requirements as all developers. The U.K. case follows European scrutiny of the framework: Germany’s competition authority last month secured Apple’s agreement to change rules on how developers use personal data for targeted advertising after concluding the prompts favored Apple’s own services, with related changes set to take effect in most other E.U. markets; Italy levied a fine exceeding €98.6 million in December; France imposed a €150 million penalty in April 2025; and Poland has also examined the tool. The lawsuit is one of several collective actions at the tribunal, following Alphabet’s £260 million settlement last month over alleged Android developer overcharges.