Advertisers successful in search for certification in collective claim against Google

02/09/26

On 5 August 2026, the Competition Appeal Tribunal (CAT) certified a collective action alleged to have a value of £billions, brought on behalf of UK advertisers against Google by a competition law academic, Dr Or Brook (Or Brook Class Representative Limited v Alphabet Inc. & Others [2026] CAT 65).

Google, the search engine operator, provides general search services and search advertising to advertisers. The advertisers' case is that Google holds dominant positions in a number of relevant markets, including general search and search advertising.

The advertisers argue that Google engaged in an abuse of its dominant position to secure the pre-installation and default status of Google Search and Chrome, thereby restricting advertisers' ability to use competing advertising platforms. They contend that this conduct allowed Google to charge supra-competitive prices for search advertising, so that they paid more, and obtained a lower return on their advertising spend. The claim is brought on a hybrid follow-on and standalone basis, relying in part on the European Commission's 2018 Google Android decision.

The main issue at the hearing was whether the proceedings should be certified on an opt-in or opt-out basis. The Tribunal ruled that the balance was in favour of opt-out proceedings.

The Tribunal also considered the appropriate rate of remuneration for PCRs. It held that, on the facts of the case, Dr Brook's hourly rate of £250 per hour, capped at £750 per day, was not excessive.