A multinational operating in the United Kingdom faces a sharpened enforcement environment in 2025. The Competition and Markets Authority has signalled that it will pursue cartel conduct, abuse of market dominance, and incomplete merger notification with greater intensity than in any prior period since Brexit. Penalties now reach up to ten percent of a group's global annual turnover – and the authority has the power to impose them without a court order.
The Competition and Markets Authority (CMA) has expanded its enforcement toolkit through updated procedural rules that took effect in early 2025. Reinforcing its capacity to investigate anti-competitive agreements, penalise abuse of a dominant market position. Additionally, block or unwind transactions that meet the merger notification thresholds. Businesses with UK revenues above designated thresholds, or those active in markets where the CMA has identified strategic concerns, are directly in scope. Companies must review their competition compliance programmes before the CMA opens a formal case – because once an investigation begins, the window for voluntary cooperation narrows sharply.
This alert outlines the key regulatory changes, identifies the business categories most exposed, and sets out the immediate steps international companies should take.
What changed and when it took effect
The CMA's updated procedural guidance entered into force in the first quarter of 2025. Three developments define the new enforcement posture.
First, the authority has confirmed that it will use its expanded investigative powers – granted under post-Brexit competition legislation – to conduct unannounced inspections, compel document production, and interview individuals under caution. These powers mirror, but in some respects exceed, the tools available to the European Commission before the UK's departure from the EU single market.
Second, the CMA has published revised leniency programme guidance. The leniency programme offers immunity or penalty reductions to cartel participants who self-report. The revised guidance clarifies the conditions for immunity, narrows the window for marker applications, and raises the evidentiary standard required to secure a reduction. A business that previously relied on informal assumptions about leniency eligibility should treat those assumptions as outdated.
Third, the merger notification regime has been recalibrated. The CMA now scrutinises transactions where one party has a share of supply above a specified level in any UK market segment – not merely those where combined UK turnover exceeds the traditional threshold. Digital markets, pharmaceutical licensing, and infrastructure assets are identified as priority sectors for closer merger review.
For international groups, the practical consequence is that a transaction structured primarily outside the United Kingdom may still trigger a mandatory or voluntary notification obligation if it affects supply conditions in a UK market.
Who is affected and the compliance deadline
The following categories of business face the highest immediate exposure.
- Groups with UK revenues above the turnover threshold in their sector, particularly those active in digital platforms, financial services, energy, and pharmaceutical supply chains.
- Companies that hold a position of market dominance – defined by reference to supply share, pricing power, and barriers to entry – in any identifiable UK product or geographic market.
- Parties to distribution agreements, licensing arrangements, or joint ventures that contain price-related or market-allocation provisions, even where those provisions were accepted as standard practice before 2025.
- Acquirers in M&A transactions that affect UK supply markets, regardless of whether the target is incorporated in the United Kingdom or registered at Companies House.
The Financial Conduct Authority (FCA) and, in legacy matters, the Financial Services Authority (FSA) retain concurrent competition powers in financial services. The CMA and FCA coordinate investigations where conduct spans both regimes. HMRC also shares information relevant to competition investigations where tax-related evidence is pertinent.
The High Court and, on appeal, the Supreme Court of the United Kingdom retain jurisdiction to hear private damages claims arising from CMA infringement decisions. Follow-on litigation before the High Court has accelerated: claimants now move quickly after a CMA infringement finding, and limitation periods are shorter than many international businesses assume.
There is no single universal compliance deadline. However, businesses that have not updated their competition compliance documentation since before 2025 should treat the entry into force of the CMA's revised guidance. early 2025. as the effective date from which prior compliance gaps become actionable. Any agreement, practice, or transaction entered into after that date without a fresh competition review carries amplified risk.
For a tailored strategy on competition compliance and CMA investigation response in the United Kingdom, reach out to our competition law team in the United Kingdom at info@ferrazwhitmore.com.
Immediate actions for international companies
Five steps should be completed without delay.
- Audit existing agreements. Review all distribution, licensing, joint venture, and supply agreements with UK-connected parties. Identify provisions that touch on pricing, resale price maintenance, market allocation, or customer restrictions. Flag any that have not been assessed against current UK competition legislation.
- Assess market position. Determine whether any group entity holds a dominant position in a UK market. Market dominance is assessed by reference to supply share, customer dependence, and structural barriers. A position that appeared non-dominant under prior thresholds may now fall within the CMA's enforcement focus given revised sector-specific guidance.
- Review pending and recent transactions. Any transaction signed or completed after early 2025 that affects UK supply markets should be reviewed against the updated merger notification criteria. If a notification obligation was overlooked, voluntary engagement with the CMA is preferable to awaiting an enforcement notice.
- Evaluate leniency eligibility. If the business is aware of conduct that may constitute a cartel – price-fixing, bid-rigging, or market-sharing – assess eligibility under the revised leniency programme immediately. The marker system operates on a first-come basis. Delay forfeits the opportunity.
- Update the internal compliance programme. Revise competition training materials, escalation procedures, and document-retention policies. The CMA treats the absence of an effective compliance programme as an aggravating factor when setting penalties.
International businesses with disputes arising from CMA enforcement actions should also review their position under the corporate disputes practice for the United Kingdom. There. Follow-on damages litigation and judicial review of CMA decisions are addressed in detail.
For context on how competition enforcement trends in the United Kingdom compare with developments in other European jurisdictions, the competition enforcement alert for Portugal provides a useful reference for groups managing cross-border compliance programmes simultaneously.
About Ferraz & Whitmore
Ferraz & Whitmore is an international law firm based in Lisbon, advising business clients across 46 jurisdictions. Our competition law practice supports international companies facing CMA investigations, cartel leniency applications, merger notification obligations, and follow-on damages claims in the United Kingdom. The firm combines Portuguese civil law expertise with English common law tradition – a dual capacity that is particularly relevant for groups managing competition exposure across both EU and post-Brexit UK regulatory regimes. Our dispute resolution practitioners have represented clients in proceedings before the High Court and in arbitral proceedings governed by ICC and LCIA rules. Additionally. Our team works closely with specialist local counsel before the Competition Appeal Tribunal. As a law firm in the United Kingdom context with a Lisbon base and 15 practice areas, we serve institutional investors, multinational groups, and in-house legal teams who need results-oriented counsel across multiple legal systems. Engaging a lawyer with United Kingdom competition experience at the earliest stage of a CMA inquiry materially affects the range of outcomes available. To discuss your situation, contact us at info@ferrazwhitmore.com.
Disclaimer: This publication is provided for informational purposes only and does not constitute legal advice. The information herein should not be relied upon as a substitute for professional legal counsel tailored to your specific circumstances. Ferraz & Whitmore assumes no liability for actions taken or not taken based on the contents of this material. For advice regarding your particular situation, please contact info@ferrazwhitmore.com.