CMA Rules on Google Search: What UK Businesses Need to Know

The UK Competition and Markets Authority (CMA) designated Google with strategic market status (SMS) in general search and search advertising on 10 October 2025. In June 2026 it imposed its first three conduct requirements: a publisher requirement on 3 June, and fair ranking and data portability requirements on 17 June. A fourth requirement, on user choice, is still under consultation. Together these rules change how Google must treat UK businesses whose customers find them through search.

Key takeaways

The CMA designated Google with strategic market status in UK search on 10 October 2025, which is not a finding of wrongdoing.
From 17 December 2026, Google must rank organic UK results without regard to whether a business advertises with Google.
Google must give 15 to 30 business days' public notice of material ranking changes before they reach the UK.
Publishers must be able to opt out of Google's AI features without being downranked, with the publisher rules in force from 3 December 2026.

What happened

The SMS designation was made under the Digital Markets, Competition and Consumers Act 2024. The CMA found that Google has substantial and entrenched market power, with more than 90% of UK searches taking place on its platform. AI Overviews and AI Mode are within scope. The Gemini assistant is not. The CMA stressed that the designation is not a finding of wrongdoing and that it imposed no immediate obligations. Instead, it allows the CMA to set targeted conduct requirements.

The timeline since then:

Date	Step
10 October 2025	SMS designation confirmed
28 January 2026	Consultation on proposed conduct requirements
3 June 2026	Publisher conduct requirement imposed
17 June 2026	Fair ranking and data portability conduct requirements imposed
23 September 2026	Further consultation on a strengthened user choice requirement (responses closed 9 October)

The publisher conduct requirement

This requirement says Google must give publishers "effective controls to withhold their Search Content" from use in its generative AI, covering both training and grounding for AI Overviews, AI Mode and services such as Gemini. Controls for search AI features must work at directory level and page level. After the consultation, the CMA also required an opt-out from AI fine-tuning. Google must attribute content clearly in AI answers, give publishers "clear and detailed metrics" on how users engage with their content in AI features, and must not penalise anyone for opting out, "for example by downranking their Search Content".

The CMA's notice says the requirement comes into force six months after 3 June 2026, which is 3 December 2026. The page-level grounding control has nine months, which is 3 March 2027. Google has already launched a site-wide Search Console toggle. It began testing with UK sites on 3 June 2026 and rolled it out worldwide by 31 August 2026.

The fair ranking conduct requirement

This one matters to almost every UK website. It covers organic results, including within AI Overviews and AI Mode, but not paid ads. Google must use "objective and non-discriminatory criteria" and must not take into account whether a business:

advertises with Google;
has other commercial arrangements with Google;
has opted out of Google's AI features; or
has exercised legal rights against Google.

Google must also give public notice of material ranking changes before they reach the UK. The notice period is at least 30 business days for changes publishers can act on, and at least 15 business days for other significant changes it can explain. It must provide feedback routes for publishers hurt by a change, and proper handling of reconsideration requests after manual actions. A dispute mechanism is also required for sites manually removed from the index. The requirement comes into force six months after 17 June 2026, which is 17 December 2026.

Data portability and user choice

The data portability requirement puts Google's existing UK Data Portability API on a legal footing. Users can send their search data to authorised third parties, and Google had three months to comply. The user choice proposal would bring choice screens for search services on Android and Chrome, with yearly prompts. AI assistants could appear on those screens if they meet the criteria. The CMA expects a final decision by the end of 2026.

What this means for UK businesses

Will Hayter of the CMA said that "clearer, predictable and more transparent ranking systems could give them greater scope to expand and invest". In practice:

Ad spend cannot buy organic rank. This was already Google's stated policy. It is now a legal obligation for UK results.
Advance warning of ranking changes. From 17 December 2026, UK businesses should get notice and an explanation before material ranking changes. That gives agencies and in-house teams time to prepare instead of reacting after a traffic drop.
A formal route to complain. If a change or manual action hits you unfairly, there will be a defined process. If at least 50 publishers raise the same change within 30 business days, Google must pass details to the CMA.
Real choice over AI. Any site can now opt out of Google's AI features without that choice counting against its normal rankings. Whether it is wise to opt out is a separate question.

These rules will not stop traffic falling when AI answers replace clicks. They regulate how Google ranks and uses content, not how much traffic it sends.

What to do now

Diarise the dates. 3 December 2026 for the publisher rules, 17 December 2026 for fair ranking and 3 March 2027 for page-level AI controls.
Watch for Google's change notices. Once fair ranking is in force, Google must publish notice of material changes in advance. Assign someone to monitor Google Search Central and the Search Status Dashboard.
Keep evidence. Record traffic, rankings and site changes over time so you can make a credible case if you ever use the complaint or reconsideration routes. On paid plans, MakeItFlow keeps scan history and runs scheduled re-scans, which helps show that a drop was not caused by a technical change on your side.
Get the technical basics right first. Fair ranking does not protect a site Google cannot crawl. Run a free website audit with MakeItFlow to check robots.txt, sitemaps, canonicals and broken links. See our guides to robots.txt and XML sitemaps.
Make a deliberate decision on AI features. Review the Search Generative AI report in Search Console before you use the opt-out toggle.

Frequently asked questions

Does strategic market status mean Google broke the law?

No. The CMA has said that designation "is not a finding of wrongdoing". It gives the CMA powers to impose forward-looking conduct requirements. Breaching those requirements once they are in force is a separate matter the CMA can enforce.

Will Google now announce core updates in advance in the UK?

The fair ranking requirement says Google must give public notice of "material changes" at least 15 or 30 business days in advance, depending on the type of change. It comes into force on 17 December 2026. Exactly how Google will apply this to core updates is not yet clear.

Do the rules cover Google Ads?

No. The fair ranking requirement explicitly excludes paid-for search results. It covers organic web, image and video results and organic results within AI features.

Google AI Mode and AI Overviews in the UK: The Impact on Clicks: AI Mode has been live in the UK since July 2025 and studies show fewer clicks when AI Overviews appear. What the evidence means for UK search traffic.

CMA Rules on Google Search: What UK Businesses Need to Know