UK Merger Control Update Webinar – Key takeaways

On 13 November 2025, Bird & Bird's UK Competition law experts Dr. Saskia King, Ariane Le Strat and Emma Bermingham, alongside guest panellist Cristina Caballero Candelario, Principal at Fingleton, and former Assistant Director of Mergers at the CMA (UK’s Competition and Markets Authority) hosted a webinar exploring the most significant changes to UK merger control following the Digital Markets Competition and Consumers Act (DMCCA), as well as other recent policy developments.

If you missed the webinar, below is a recap of key takeaways.

The DMCCA: A New Era for UK Merger Control

The DMCCA represents the most significant overhaul of UK merger control rules in decades. The CMA now has three pathways to obtain jurisdiction over a transaction:

• Turnover Test: The UK turnover threshold has increased from £70 million to £100 million to account for inflation.
• Share of Supply Test: This test remains at 25% share of supply, but now includes a new small merger safe harbour requiring at least one merging party to have UK turnover over £10 million. The test still offers the CMA enormous discretion as it can capture the share of supply of any reasonable description of goods or services.
• Hybrid Test: This new test allows the CMA to claim jurisdiction where one party has UK turnover over £350 million and a 33% UK share of supply, and the other party has a UK nexus - which can be as minimal as having UK customers, even without physical UK presence. This test has been mainly designed to capture "killer acquisitions" where companies eliminate future competition by acquiring early-stage businesses.

The DMCCA has also granted the CMA enhanced enforcement powers, with fines now standing at 10% of global turnover for companies and up to £30,000 for individuals for fixed amounts, and up to 5% of daily turnover and £15,000 for individuals for daily rates, for supplying false or misleading information.

It is worth noting that last month the UK government announced a consultation on legislative reform which hinted at the share of supply test being updated in the near future. We will be following this closely so keep an eye out for future updates on this point from our competition team.

The 4Ps: A New Practical Framework

The CMA has introduced the 4Ps framework - Pace, Predictability, Proportionality and Process - representing a change in approach aimed at prioritising economic growth whilst maintaining effective competition regulation.

• Pace: The CMA will aim to complete pre-notification within 40 working days, and it is now also working towards a 25 working day clearance for straightforward Phase 1 cases instead of the previous timing which was at around 35 working days. Businesses should expect earlier and more robust engagement with the CMA, making it crucial to have well-prepared strategies with the right evidence and strategic narrative upfront.
• Predictability: Whilst the CMA has published new guidance clarifying how it plans to apply jurisdictional tests, the regime hasn't become significantly more predictable as the legal framework remains very broad. However, we expect the CMA to have less appetite for cases where jurisdiction is on the margins.
• Proportionality: The CMA has announced a "wait and see" approach, focusing on deals affecting UK local or national markets and deprioritising those involving exclusively global (or wider than national) markets where other competition authorities are reviewing. On a separate note, the new draft remedies guidance signals greater openness to behavioural remedies and complex hybrid solutions.
• Process: The Mergers Charter commits the CMA to earlier and direct engagement with senior business leaders, making it critical that senior executives are well prepared for these
  engagements.

Key Trends

The Mergers Intelligence Unit (MIU) monitors merger activity through different information, including public sources and third-party complaints, with intelligence flowing into the Mergers Intelligence Committee (MIC), which meets weekly to decide whether to investigate deals.

Statistics for the 2024/25 financial year show an increase in the number of transactions being reviewed by MIC (over 1,000), as well as in the number of briefing papers submitted. However, the number of transactions called in for formal notification has remained relatively stable. As regards Phase 1 investigations, there has been a decrease in the number of investigations and an uptick in de minimis cases following the threshold increase to £30 million. As regards Phase 2, just seven cases were referred in the 2024/25 financial year. Notably, the Vodafone/Three transaction was approved with behavioural remedies - the first time the CMA approved a four-to-three transaction in the telecoms sector using this approach.

Practical Guidance for Deal Teams

• Pre-Notification: Early engagement with the CMA is essential, and merger parties should be prepared for detailed jurisdictional analysis and understand the implications of making public announcements.
• During Investigation: Establishing good rapport with the case team, providing swift responses to RFIs, and investing in robust economic evidence at the outset will pay dividends. Always provide
  true, accurate and evidence-based information, as the consequences for failing to do so are now more severe than ever.
• Briefing Papers: Briefing papers should be limited to five pages and typically require a signed merger agreement.

If you have any questions about these developments, or need guidance, please reach out to our speakers, all of whom have previous experience working at the CMA.

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You might also be interested in registering for our upcoming webinar on 25 November 2025 Navigating the New Era of FDI Screening – Sensitive Sectors and Cross-Border Deals.

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