Competition and Markets Authority
In short
The Competition and Markets Authority (CMA) is the UK's competition and consumer watchdog. In AI it reviews big tech deals and partnerships, and can set binding rules for firms like Google that dominate key digital services.
- Also called
- CMA, UK competition regulator
- Topic
- Law, policy and the UK
- Level
- Beginner
- First described
- Established as a body corporate by section 25 of the Enterprise and Regulatory Reform Act 20132.
The CMA is an independent non-ministerial government department. It investigates mergers that could reduce competition, acts against cartels and anti-competitive behaviour, protects consumers and promotes competition in digital markets1. It was created by the Enterprise and Regulatory Reform Act 20132.
It turned to AI early. In September 2023 its review of foundation models, the large models behind tools like ChatGPT, proposed seven principles, including access to key inputs, a mix of open and closed models, freedom to switch between models, and fair dealing with no anti-competitive self-preferencing, tying or bundling3.
Its sharpest tool comes from the Digital Markets, Competition and Consumers Act 2024. The CMA can designate a firm as having "strategic market status" in a digital activity linked to the UK if it has "substantial and entrenched market power" and "a position of strategic significance"4. This regime started on 1 January 20255.
In October 2025 the CMA gave Google strategic market status in general search and search advertising, noting it handles more than 90% of UK searches. AI Overviews and AI Mode are in scope; the Gemini assistant is not, though the CMA said it would keep that under review5.
The CMA also checks whether AI tie-ups count as mergers. In March 2025 it decided Microsoft's partnership with OpenAI did not qualify for a merger investigation6.
Example
On 3 June 2026 the CMA ordered Google to let publishers, such as UK news sites, block their content from powering AI features in search such as AI Overviews, and opt out of it being used to fine-tune AI models. Google must also credit their content with clear links, and was given nine months to make the changes7.
Why it matters
Search, cloud and AI models are dominated by a few very large firms. The CMA is the UK body that can make them change how they treat rivals, publishers and users.
Questions people ask
What is strategic market status?
A designation under the Digital Markets, Competition and Consumers Act 2024 for firms with "substantial and entrenched market power" and "a position of strategic significance" in a digital activity linked to the UK4. The CMA can then impose conduct requirements, as it did for Google search in 20267.
Does the CMA regulate AI?
Not AI as such. It applies competition and consumer law to AI markets: reviewing deals such as Microsoft and OpenAI's partnership6, and setting rules for designated firms, including for Google's AI Overviews57.
Can publishers stop Google using their content in AI Overviews?
Yes, under a CMA conduct requirement imposed on 3 June 2026. Google must let publishers block their content from powering AI features such as AI Overviews, let them opt out of fine-tuning, and credit their content with clear links. Google had nine months to comply7.
Related terms
Sources
- Competition and Markets Authority, About us (GOV.UK)
- Enterprise and Regulatory Reform Act 2013, section 25
- CMA press release (18 September 2023), Proposed principles to guide competitive AI markets and protect consumers
- Digital Markets, Competition and Consumers Act 2024, section 2
- CMA press release (10 October 2025), CMA confirms Google has strategic market status in search services
- CMA case page, Microsoft / OpenAI partnership merger inquiry
- CMA press release (3 June 2026), CMA secures fairer deal for publishers and improves Google search services in UK