The Competition Appeal Tribunal certified a Google search advertising claim covering roughly 880,000 UK businesses, and it did so on an opt-out basis: those advertisers are in the class unless they act to leave, not the other way round. The tribunal reached that outcome by rejecting the argument Google itself made against it, that the class was too large to notify and to pay. Certification settled how the case proceeds. It settled nothing about whether Google did anything wrong.
The Opt-Out Certification, and the Case Behind It
The judgment, dated 5 August 2026, was handed down in case 1720/7/7/25, Or Brook Class Representative Limited v Google Inc & Others, before the Competition Appeal Tribunal. A panel chaired by Mr Justice Meade, sitting with John Davies and Robert Herga, granted a Collective Proceedings Order and certified the claim as opt-out rather than opt-in. The class covers every UK-domiciled advertiser that paid for Google search advertising services between 1 January 2011 and 15 April 2025, minus media agencies, the class representative, and deceased individuals. Roughly 880,000 UK businesses and organisations fall inside that window, a figure supplied by the claimant side’s lawyers, not the tribunal.
Why the Tribunal Rejected Google’s Own Objection
Google opposed opt-out certification during the proceedings. Its argument: the class was too large to notify individually and too large to pay out to, and advertisers with bigger claims should be free to decide for themselves whether to join at all. The tribunal disagreed. It found that requiring advertisers to opt in individually would be “a prolonged and difficult exercise,” and it described Google’s objections to that process as a “nit-picking, negative approach.” On distribution, the panel concluded that paying an aggregate damages award out directly to identified advertisers, at a rate “far in excess” of what previous collective proceedings had managed, could reasonably be expected.
What Does Opt-Out Certification Mean for an Advertiser?
Opt-out certification means every UK-domiciled business that paid for Google search advertising between 1 January 2011 and 15 April 2025, media agencies aside, is automatically part of the claim unless it takes action to remove itself. Certification is a procedural finding about how the case proceeds, not a ruling that Google overcharged anyone, and no liability has been established. No opt-out deadline has been set, so there is currently nothing for an advertiser to decide.
The £5 Billion Figure Isn’t a Verdict
Trade coverage of the judgment attached a headline number: a claim reportedly worth up to about £5 billion, roughly $6.7bn. That figure comes from the claimant side, the class representative’s lawyers and an expert economist, not from the tribunal, and it describes what the claim could be worth, not an award. The underlying allegation is that Google’s conduct let it charge more for search advertising than a competitive market would have allowed, reducing the value advertisers got for the money feeding the same Search revenue Google reports each quarter. Google did not immediately respond to a request for comment.
The Class Representative, and the One Question It Leaves Open
The case is brought by Or Brook Class Representative Limited, a special purpose vehicle whose sole director and member is Dr Or Brook, a competition-law academic. It is not a law firm and not a litigation funder. A summary of the collective proceedings claim form was published on 1 May 2025, a carriage hearing followed in October, and the CPO hearing was heard on 8 July 2026 before judgment landed a month later. The class definition excludes media agencies by name, which leaves an open question for any brand that bought its search ads through one. This judgment doesn’t answer it.
What an Advertiser Can Actually Do Today
No opt-out deadline exists yet, so there is no decision to make today, only a record worth protecting. An advertiser’s own billing and invoice history is now the asset that matters, and the Relevant Period itself runs more than fourteen years. That is a different record to keep than a click identifier traced through an offline conversion upload. Filing away the old invoices costs nothing and closes off nothing. Deciding whether to opt out is a separate step, and it waits on a deadline the tribunal hasn’t set.
