KP Law has filed an application for a collective proceedings order with the UK Competition Appeal Tribunal. The claim, which is supported by extensive findings by courts and regulators across the globe, alleges that Google favoured its own display advertising services while excluding competitors and potential competitors, leaving advertisers paying more, for less effective display advertising. 

The total potential damages are estimated to be in the region of up to £3 billion. Any advertisers based in the UK who paid for display advertising services provided by Google, regardless of whether purchased directly or through a media agency, are included within the claim.  

‘Ad Tech’ refers to the technology facilitating online digital display advertising – that is adverts that appear on web pages or mobile apps. It is distinct from search advertising, which concerns adverts placed when internet users use search engines. Ad Tech is a set of technologies which ultimately connects advertisers with their potential clients, internet users, and which manages their automated online advertising campaigns in real time. Ad Tech technology, including the automated auctions which advertisers participate in to win advertising space with publishers, has historically been, and continues to be, dominated by Google.  

A number of similar cases are being pursued against Google. A related Ad Tech claim on behalf of UK publishers has been certified by the Competition Appeal Tribunal and, in the United States, a 2025 ruling in an antitrust lawsuit on behalf of the Department of Justice and 17 states found that Google had illegally monopolised key aspects of Ad Tech. Both cases remain ongoing. In Europe, the European Commission fined Google €2.95bn in 2025 for abuse of dominance in relation to Ad Tech, citing conduct which is also the subject of the UK advertisers’ claim. Google has appealed the European Commission’s decision.

Additionally, France’s Competition Authority imposed a €220 million fine in 2021 in relation to Google’s anti-competitive practices with respect to Ad Tech and the UK Competition and Markets Authority issued a Statement of Objections against Google’s Ad Tech practices in 2024 in its own investigation, which is ongoing.  

KP Law and the proposed class representative said in a statement: “Google has a well-documented track record of anti-competitive behaviour in the online digital advertising space, in particular in relation to Ad Tech, as recognised by courts and regulators across the US and Europe. It is only right that UK advertisers have their day in court and that Google now answers for its entrenched and longstanding anti-competitive behaviour. We look forward to working on behalf of advertisers to secure compensation for them from Google.” 

The KP Law team acting on the case is led by KP Law’s head of competition litigation Duncan Hedar, together with Emma Birch and James Matthews. The proposed class representative is AGC Collective Actions Limited, acting through former Eversheds Sutherland competition law partner, Adam Collinson. Mr Collinson has instructed economic expert firm Keystone AI, whose team is headed by Dr Andrea Coscelli, the former head of the Competition and Markets Authority. The counsel team includes Mark Brealey KC and Nicholas Khan KC (both of Monckton Chambers) and Adam Aldred (Kings Chambers).