We are bringing an action seeking damages for losses caused by Google at the UK Competition Appeal Tribunal.

That could include you.

What has happened?

In 2021, Google was fined by the French Competition Authority for abusing its dominant position in relation to ad tech services. It’s possible that all UK-based Publishers (and if applicable, their Publisher Partners) that received revenue from the sale of online display ads between 1 January 2014 and 30 November 2022 have suffered financial loss by Google too. On 17 April 2025 judgment was given against Google in the USA, in a similar case brought by the US Department of Justice. On 5 September 2025 the European Commission adopted an infringement decision against Google for its conduct and subjected Google to a €2.95 billion fine. The US Department of Justice and European Commission are yet to hear arguments on an appropriate remedy to resolve the infringements looking forwards; a remedies trial starts in the US on 22 September 2025 and Google has 60 days to make proposals to the European Commission from the date of its decision.

A further investigation into Google’s conduct by the UK Competition and Markets Authority is ongoing.

Who is involved?

Ad Tech Collective Action LLP, the class representative led by Claudio Pollack, Charles Arthur and Kate Wellington, alleges that Google abused its dominant position, causing financial harm to those who published content on websites or apps (Publishers). The supporting team is made up of expert competition lawyers and economists.

If you are a Publisher you do not need to take any steps to be involved. You are included in the Class unless you opted out of it prior to 4pm on 28 May 2025. On the other hand, ‘Publisher Partners’ – resellers of online display ads on behalf of Publishers – must have actively opted in by 4pm on 28 May 2025 to be part of the action. If you are a Publisher or Publisher Partner that did not opt into or out of the claim by 4pm on 28 May 2025 but you now wish to do so, please see the “What do I need to do now?” section in the FAQs.

The costs of the claim are fully funded so class members will not have to cover any costs.

We welcome all expressions of support, regardless of whether you own a website or mobile app.

What is ad tech?

Simply put, ad tech is the technology powering the online ads that billions of consumers see in their everyday lives, be it on a desktop computer, tablet or smartphone. Digital advertising has experienced spectacular growth, exceeding $490 billion in 2021, so it’s no surprise that selling digital ads has become a key source of revenue for publishers of online content.

Who’s the Class Representative?

Ad Tech Collective Action LLP is the Class Representative. It is a limited liability partnership that has been incorporated to manage the claims against Google. The members of the partnership are Claudio Pollack, Charles Arthur, and Kate Wellington.

Claudio Pollack has spent more than 10 years in Director level roles at Ofcom and is experienced in competition, consumer, and small business matters. Charles Arthur has been a leading technology and science journalist and editor for more than 30 years – and during that time, he has written for various national publications, including The Guardian, The Daily Telegraph, and The Independent. Kate Wellington is a lawyer by background (including in competition litigation matters) and runs the Costs Lawyer Standards Board. Kate also led the campaigning and policy arm of the legal team during her time at Which?.

Claudio, Charles, and Kate are championing the cause for UK website and mobile app owners, who should have earned more from their ad sales between 1 January 2014 and 30 November 2022.

What has Google done?

Google is the largest and most important ad tech vendor at every step of the value chain, with very high market shares, for example, as high as 90-100% in the publisher ad server market. But after a complaint by news publishers in 2019, the French Competition Authority established that Google had infringed Article 102 of the Treaty on the Functioning of European Union. Google had been using practices which ensured that its ad server favoured its own ad exchange, AdX, and vice versa, as well as ensuring that its demand-side platforms, Google Ads and DV360, also favoured AdX.

Why is it wrong?

This is a clear breach of Article 102, which prohibits undertakings in this dominant position from abusing their advantage. According to the decision, Google’s conduct inflicted considerable financial losses to publishers, by depressing their revenue in two different ways.

1.
Google’s actions deprived publishers of the ability to benefit from undistorted competition between ad exchanges, which could have exerted pressure on Google to lower its very high AdX fees, at around 20%.

2.
Google’s conduct also limited competition and prevented publishers from achieving higher prices for their impressions.

Google’s ad tech practices are also under scrutiny in lawsuits and investigations around the world, including ongoing investigations by the UK Competition and Markets Authority, the European Commission and the Australian Competition & Consumer Commission, and lawsuits brought by a coalition of US State Attorneys General and by the US Department of Justice respectively.