United Kingdom: A Separate Regime Since Brexit

Britain’s competition regulator has done something Brussels has not: forced Google to report search impressions and click-through rates separately, and secured publishers an opt-out from AI Overviews arriving December 2026. For two years the argument about AI Overviews and publisher traffic was stuck — publishers produced data showing steep declines, Google said the data was flawed, and nobody could check because the only party holding auditable numbers had not published them. That stalemate now has an end date, set by a competition regulator rather than a copyright court. It is the clearest illustration of why UK digital marketing needs its own analysis rather than a footnote in a European one.

A country analysis from Digital, Ecommerce & Performance Marketing in Europe. The UK sits outside the DMA, the DSA and the EU AI Act — read this rather than assuming the European pages apply. Not legal advice. Last reviewed August 2026.

1. Four regimes the UK is outside

The single most common planning error in UK performance marketing is assuming European rules apply because the geography feels adjacent. They do not.

Summary of the post-Brexit divergence. Note the important qualification: a UK business serving EU users is still caught by EU rules including the AI Act’s extraterritorial reach, so “outside the regime” describes the domestic position rather than a blanket exemption.

The UK is not a lighter version of Europe. It is a separate jurisdiction that happens to share a continent, and in one respect it has moved further than the EU has.

2. The DMCCA regulates firms, not categories

This structural difference matters more than most comparisons acknowledge. The Digital Markets, Competition and Consumers Act 2024 created a Digital Markets Unit within the CMA with power to designate an undertaking as having Strategic Market Status where it has substantial and entrenched market power and a position of strategic significance in a digital activity.

Sources: DMCCA 2024 as described in 2026 legal analyses; the regime is reported as taking effect from 1 January 2025 with the Act itself in force from 6 April 2025 — sources differ slightly on which date to cite, so verify if the precise commencement matters to you.

The trade-off is real. Brussels moved faster because its obligations applied automatically. London has moved more slowly but has been able to design remedies aimed at specific, evidenced problems — which is how it arrived at requirements the DMA has not produced.

3. What the CMA actually imposed on Google

Sources: CMA case page for Google’s general search and search advertising services, and 2026 legal analyses. The designation drew evidence from Google, over 80 market participants and 34 consultation responses. Scope covers Google Search, search advertising including Google Ads and SA360, AI Overviews and AI Mode as part of general search infrastructure, and Google Discover.

Note what falls inside the designation. Google Ads and SA360 are explicitly named, as are AI Overviews and AI Mode, on the basis that they form part of general search infrastructure and appear directly on the results page. Google Discover is covered too. This is not a narrow ruling about organic listings.

4. The AI Overviews finding nobody expected

Buried in the CMA’s 156-page decision is a figure that cuts against the loudest narrative in search marketing. The regulator found that AI assistants constitute only 0 to 5% of the volume of Google Search queries when measured by search-grounded queries.

Source: CMA final decision of 10 October 2025 at paragraph 5.30, finding AI assistants constitute 0 to 5% of Google Search query volume measured by search-grounded queries; Google’s UK search share of roughly 91% across devices per StatCounter. Read the qualifier carefully — this measures search-grounded queries at a point in time and does not measure AI use generally, nor the effect of AI Overviews on click-through from queries that still occur.

The finding is useful precisely because of who produced it. A competition regulator with information-gathering powers, examining the question adversarially, arrived at a number far below what vendor commentary implies. Treat it as a corrective to the discourse rather than as proof that nothing is changing.

5. Separate impressions and click-through reporting

This is the change with the most direct effect on day-to-day UK performance marketing, and it deserves more attention than it has received.

The conduct requirements imposed in June 2026 are reported to include impressions and click-through rates being reported separately, alongside a publisher opt-out arriving in December 2026 and fair ranking and data portability obligations.

Based on CMA case updates of 3 June and 17 June 2026 and reporting on the conduct requirement package. Precise implementation detail should be taken from the CMA’s published decisions rather than from summaries.

Until now a UK publisher watching traffic fall could not tell whether it was appearing less often or being clicked less often. Those are different problems with different responses, and the regulator has just separated them.

For anyone running UK ecommerce marketing on organic search, that split is the difference between a visibility problem you fix with content and coverage, and a click problem you fix with titles, snippets and intent match.

6. Privacy: UK GDPR and PECR

The UK operates UK GDPR alongside the Privacy and Electronic Communications Regulations, enforced by the Information Commissioner’s Office, with penalties reported at up to £17.5 million or 4% of annual turnover.

The practical position for marketers closely resembles the European one: cookies and similar technologies require consent, and the ICO has been active on website compliance. The divergence is more institutional than substantive — a different regulator, a different appeal route, and a UK government that has publicly pressed regulators to support growth, a pressure the Information Commissioner has responded to by stressing the ICO’s independence.

Comparative summary. Both regimes are in flux and this table describes the position as at August 2026 — confirm current requirements before relying on any row, particularly the last.

7. Where the UK is more permissive

Three areas where UK practice gives more room than the strictest European markets.

Based on 2026 compliance analyses. Permissive is not the same as unregulated. UK B2B email still requires a functional opt-out honoured across systems, and a UK business serving EU users remains subject to EU rules regardless of its domestic position.

8. The UK looks more American than European

On several commercial measures the UK behaves less like the continent than its geography suggests, and planning it as part of a European bloc misreads it.

Comparative assessment drawing on figures used elsewhere in this cluster, including the reported ~73% Amazon share of UK retail media and Google’s ~91% UK search share. The comparison is directional — the UK is not the United States, but a plan built for continental fragmentation will over-engineer for it.

The practical consequence is that much of the operational complexity described in the cross-border EU analysis — multi-language storefronts, country-specific payment rails, destination VAT across 27 states — simply does not arise for a UK-only operation. UK ecommerce marketing is a single-language, single-currency, single-VAT problem, which makes it operationally simpler and commercially more competitive.

9. What this page does not cover

Scope statement. The last row is the one that catches UK businesses most often: domestic exemption from the DMA, DSA and AI Act does not help if you are serving EU customers.

10. The 90-day plan

Indicative sequencing. Splitting UK reporting comes first because the UK is on a different regulatory clock from the EU, and a combined EMEA number will average two markets whose search environments are now being changed by different regulators at different speeds.

11. Mistakes to avoid

Recurring errors in UK digital marketing planning; illustrative.

12. What changes next

The publisher opt-out lands in December 2026. When publishers can refuse participation, the composition of UK results pages may change in ways that affect both organic visibility and the context around paid placements.

The conduct requirement programme continues. The January 2026 consultation was described as the first substantive deployment of DMCCA conduct powers, and the CMA has published a roadmap for further interventions. Google’s designation is a template for how subsequent SMS cases will be handled.

Further designations are possible. The SMS mechanism applies firm by firm and activity by activity, so the regime expands through new investigations rather than by adding names to a list.

Key Takeaways

• The UK sits outside the DMA, DSA and EU AI Act — but EU rules still reach you if you serve EU users.
• The DMCCA regulates firms for specific activities, not categories, producing bespoke conduct requirements rather than a standing catalogue.
• Google received the first ever SMS designation in October 2025, covering Search, Google Ads, SA360, AI Overviews, AI Mode and Discover.
• The CMA measured AI assistants at 0–5% of Google query volume — a regulator’s corrective to the prevailing narrative.
• Impressions and click-through rates are now reported separately, letting you distinguish a visibility problem from a click problem for the first time.
• A publisher opt-out from AI Overviews arrives December 2026.
• The UK is commercially closer to the US than the continent — single language, single currency, concentrated retail media.

Frequently Asked Questions

Conclusion

Britain took the slower route to platform regulation and, in one respect, has arrived somewhere the EU has not. The DMCCA required the CMA to investigate, designate, consult and then negotiate each remedy individually — which took eighteen months longer than Brussels needed, and produced requirements aimed precisely at evidenced problems rather than at a category of firm.

The result is a set of changes that matter more to a working marketer than most of what the DMA achieved: search reporting that finally separates being seen from being clicked, a publisher opt-out from AI Overviews with a date attached, and a regulator’s finding that the AI substitution everyone is planning around currently sits between zero and five per cent of query volume. Treat the UK as its own market, split it out of your regional reporting, and check whether you are also serving EU users — because that is the one question where the UK’s separateness stops helping.

UK brands expanding into the Gulf face a different set of constraints again — see ecommerce marketing in the UAE and GCC.