£13.6bn collective adtech action against Google looms

A £13.6bn legal action against Google over alleged anti-competitive practices in online display advertising has cleared another hurdle after the Competition Appeal Tribunal granted a collective proceedings order in the claim.

The decision allows UK publishers’ claims, brought by Ad Tech Collective Action LLP, to proceed as a collective action.

The British claim, which is being supported by similar action in the Netherlands, is seeking compensation for lost revenue from the sale of advertising space on the websites of news publishers and any site funded by online ads, nearly 200,000 businesses.

The claim is being brought by Ad Tech Collective Action (ATCA), led by Claudio Pollack, Charles Arthur and Kate Wellington, who allege that Google abused its dominant position in the adtech market and caused significant loss to UK online publishers.

ACTA argues that Google’s alleged anti-competitive behaviour has harmed publishers by “dictating terms, controlling pricing” and “favouring its own platforms” in the process of selecting ads displayed online. These practices, the lawsuit claims, have reduced publisher advertising revenue by up to 40%.

The proceedings in the Competition Appeal Tribunal follow international scrutiny of Google’s ad tech practices. Authorities in France, the UK, the EU and the US have launched investigations, with France already imposing a €220m fine. The case now proceeds in parallel with these global actions.

Kate Wellington said: “With the collective action now advancing, Google can be held accountable for its actions. We are committed to ensuring that affected publishers and Publisher Partners have the opportunity to receive fair compensation for the harm we allege they have suffered.”

UK domiciled publishers who received ad revenue from online display ads (ads displayed on a publisher’s website or mobile app alongside content) between January 1 2014 and November 30 2022 are automatically included in the claim unless they take steps to remove themselves (‘opt out’) before 4pm on May 28 2025.

‘Publisher partners’ – resellers of online display ads on behalf of publishers – must opt in to be part of the claim before 4pm on May 28 2025.

Excluded from the claim are Google employees, legal teams, CAT members and certain other categories outlined in the full CPO notice accessible here>