Introduction

Google has dominated online search for more than two decades. Now, a £5 billion competition claim against the company has cleared a major hurdle in London.

On 5 August 2026, the Competition Appeal Tribunal (CAT), the specialist court that hears UK competition cases, certified a collective action against six Google entities on behalf of around 880,000 UK advertisers, seeking roughly £5 billion in damages.

A collective action lets a large group affected by the same alleged problem bring one case together, instead of hundreds of thousands of separate lawsuits. This one is opt-out, meaning eligible advertisers are automatically included unless they choose to leave.

Certification doesn't mean Google has done anything wrong. It just means the case can proceed to be tested properly. But it raises a bigger question: when does a successful company cross the line from competing well to using its power to stop others competing?

What is Google Being Accused of?

The claim centres on abuse of dominance, a company using significant market power in a way that harms competition. Being dominant isn't illegal; abusing that dominance is.

The advertisers allege Google reinforced its position through Android/Chrome/Play Store agreements, payments to browser makers to set Google as the default search engine, and conduct around its SA360 advertising tool. The claim is that these combined to make Google's platform harder to avoid, and let it charge more for search ads than it could in a genuinely competitive market.

Google building a good product isn't the problem. The real question is whether its dominance came from fair competition, or from making it harder for rivals to get a look-in.

Why Does This Matter?

Access to Google's users is hugely valuable to advertisers. A win here could mean a large damages bill for Google, and could reshape how tech platforms structure deals with browsers, device makers and advertisers.

There's also a forward-looking angle. As AI assistants change how people search for information, companies that already control search engines, browsers and operating systems may carry that advantage into AI. This isn't an AI case, but the underlying question, about how much advantage a dominant company can carry into the next market, is likely to matter increasingly for AI too.

Impact on Law Firms

Google is represented by Simmons & Simmons. A case like this typically pulls in:

  • Competition: arguing whether Google is dominant, whether its conduct was abusive, and whether that conduct caused the alleged losses — working closely with economists on market share and pricing evidence.
  • Dispute Resolution: managing evidence, procedure and case strategy for a claim with ~880,000 potential claimants.
  • Technology: explaining how Google's search, browser, Android and ad products actually interact.
  • Commercial/Contracts: reviewing the underlying agreements with device makers, browsers and advertisers.

What Happens Next?

Certification is only step one; the substantive allegations still need to be tested. For aspiring competition lawyers, this case has it all: dominance, digital markets, economics and complex litigation, built around one question.  When does being very good at competing become stopping others from doing the same?