UK app developers’ action against Apple’s App Tracking Transparency framework

More than 13,000 UK app developers could be eligible for compensation if a £2 billion collective action concerning Apple’s App Tracking Transparency (ATT) framework succeeds.

What happened?
 
ATT Collective Action Limited, whose director Ann Pope is the former Senior Director for Antitrust at the Competition and Markets Authority, filed the collective action with the Competition Appeal Tribunal (CAT) in September 2026.
The claim alleges that Apple imposed unfair and discriminatory privacy requirements on third-party iOS app developers compared with those applied to its own advertising and data-collection activities. These requirements are said to have made it harder for developers to generate advertising revenue, attract users and sustain free-to-use apps.

What is ATT?

In 2021, Apple’s ATT framework introduced rules for third-party app providers on the use of data on iPhones and iPads. Third-party iOS apps must obtain user consent under data protection law, as well as an additional consent through a prompt predefined by Apple. These ATT rules do not apply to Apple’s own apps, and Apple uses its own prompt to request user consent to personalised advertising.

The legal case 

The claim alleges that Apple abused its power and discriminated against third-party iOS app developers by requiring them to obtain consent through Apple’s prescribed prompt in addition to consent required under data protection law, while applying less burdensome requirements to its own advertising and data-collection activities.

The claim further alleges that Apple introduced ATT unilaterally, without proper consultation or sufficient time for developers to adapt their business models to avoid significant losses.

The collective action

The claim is brought on an opt-out basis on behalf of UK app developers falling within the proposed class definition. It seeks to represent those developers automatically unless they actively choose to opt out. The legal action is being funded by a commercial litigation funder, and class members will not pay costs or fees to participate.

Specialist team

Hausfeld is a leading disputes-only law firm specialising in competition law, with significant expertise in all aspects of collective redress and group claims, including litigation against Big Tech and other large corporates. Hausfeld notably led Dr Rachael Kent’s successful £1.5 billion Competition Appeal Tribunal claim against Apple, which won at trial in 2025.

Have you been affected?

If you are a UK app developer who, between 26 April 2021 and 3 September 2026, generated revenue from advertising within a third-party iOS app and/or spent money on advertising to attract users to a third-party iOS app, you may be entitled to compensation if the claim succeeds. appleapptrackingclaim.co.uk