What The Proposed Changes To UK Merger Rules Mean For Your Business

A business acquisition can appear complete on paper long before the Competition and Markets Authority (CMA) considers it finished. In the UK, a transaction can still be called in for investigation months after completion, potentially delaying integration, disrupting operations and affecting deal value long after the parties believed the transaction had closed.

The government is now proposing reforms to the UK merger control regime. While the stated aim is to make the system more efficient and business-friendly, the changes do not remove the underlying uncertainty that many buyers, sellers and investors continue to face. For businesses considering acquisitions, investments or strategic partnerships, understanding how these reforms may affect transaction planning is becoming increasingly important.

The UK is still retaining its voluntary notification system

One of the most significant aspects of the current UK merger regime is that businesses are generally not legally required to notify the CMA before completing a transaction. That will remain the case under the proposed reforms. At first glance, this flexibility can appear commercially attractive. It avoids the cost and delay associated with mandatory filings and allows many transactions to proceed without formal regulatory engagement.

The difficulty, however, is that the CMA retains extensive “call-in” powers. Even where a deal has already completed, the regulator may still investigate it up to four months after the transaction becomes public knowledge. That creates a level of execution risk which is often underestimated in mid-market transactions.

If the CMA intervenes after completion, the practical consequences can be significant:

• integration plans may need to be paused;
• businesses can be required to operate separately;
• management time may be diverted into a regulatory process;
• synergies anticipated in the deal model may be delayed or lost; and
• lenders and investors may reassess risk exposure.

For buyers, this is no longer simply a competition law issue. It is a transaction structuring and risk allocation issue. In practice, parties are increasingly considering CMA exposure much earlier in the transaction lifecycle, often before heads of terms are agreed. This is particularly important where:

• the parties operate in overlapping sectors;
• the target has a strong regional market position;
• the acquisition strategy involves consolidation; or
• the buyer intends rapid post-completion integration.
• The reforms may improve early-stage resolution

Under the current regime, where the CMA identifies concerns during an initial review, the parties have only five working days to propose remedies or solutions capable of addressing those concerns. In many transactions, that is an extremely compressed timetable in which to develop commercially workable proposals.

The proposed reforms would allow the CMA to extend this period by a further five working days where there is a realistic prospect of agreement being reached. Although relatively modest, this is a sensible and potentially valuable change. Resolving concerns at an early stage can avoid a far more extensive Phase 2 investigation, which may last many months and significantly increase cost, uncertainty and management distraction.

From a practical perspective, this reinforces the importance of early preparation. Businesses that have already considered possible competition concerns, market overlaps, customer concentration and potential behavioural or structural remedies are likely to be in a far stronger position if the CMA raises issues.

Deal documentation may require greater focus on regulatory risk

One area often overlooked in discussions around merger control reform is the impact on transaction documentation itself. Where there is realistic CMA exposure, parties may need to consider:

• conditionality linked to regulatory clearance;
• long-stop dates;
• obligations to cooperate with regulatory processes;
• restrictions on interim business conduct;
• allocation of regulatory risk between buyer and seller; and
• termination rights if approvals are delayed or refused.

These issues are particularly important where external financing is involved, integration forms part of the deal rationale or the transaction timetable is commercially sensitive.

Buyers should also be cautious about assuming that smaller transactions fall outside the CMA’s interest. For example, a relatively modest acquisition in a niche sector or regional market may still attract scrutiny where the parties already hold a significant combined market position.

The proposed changes to Phase 2 investigations are more controversial

The most debated aspect of the reforms concerns the structure of the CMA’s in-depth Phase 2 investigations.

Under the current system, these investigations are conducted by an independent panel which has not previously been involved in the case. That separation is intended to provide an additional level of procedural independence and fresh oversight. The government is proposing to replace this model with a system involving CMA-led decision-making committees, supported by some independent members.

Supporters of the reform argue this could improve efficiency, consistency and speed. Critics, however, have raised concerns that reducing the separation between the initial investigation team and the ultimate decision-makers may weaken confidence in the independence of the process.

For businesses involved in substantial transactions, the issue is less about constitutional theory and more about predictability and deal certainty. Where significant management time, financing arrangements and integration planning are already committed, confidence in the objectivity and transparency of the review process becomes commercially important. The reforms do not currently appear to introduce materially stronger appeal rights or procedural protections to offset those concerns.

Minority investments and strategic influence remain a risk area

Another area where uncertainty remains is minority investments and strategic partnerships. The CMA’s jurisdiction does not depend solely on outright control. In some cases, acquiring a minority stake may still fall within scope if the investor gains material influence over the target business.

The proposed reforms attempt to provide greater clarity around the factors the CMA will consider, but in practice these assessments are still likely to remain highly fact-sensitive.

This is particularly relevant for:

• private equity investments;
• joint ventures;
• strategic minority stakes;
• shareholder arrangements with enhanced veto rights; and
• staged acquisitions.

Businesses sometimes assume that acquiring less than 50 per cent automatically avoids merger control concerns. That assumption can be dangerous.

A practical administrative change

One practical reform likely to be welcomed by businesses and advisers is the proposal to pause certain statutory review periods over the Christmas and New Year period. This aligns the UK more closely with several international regimes and reflects the commercial reality that key decision-makers are often unavailable during that period.

While administrative in nature, the change should reduce unnecessary procedural pressure in live transactions.

What businesses should be doing now

The proposed reforms do not fundamentally change the reality that UK merger control remains capable of creating material transaction risk, including after completion. The key difference is that businesses are increasingly expected to manage that risk proactively rather than treat competition analysis as a late-stage legal exercise.

Before announcing or signing a transaction, businesses should consider:

• whether the parties operate in overlapping or adjacent markets;
• whether regional or niche market share could trigger scrutiny;
• whether the transaction structure adequately allocates regulatory risk;
• whether integration plans are achievable if CMA intervention occurs; and
• whether early engagement with advisers or the CMA may reduce uncertainty.

In many cases, the most valuable work is done before the formal process even begins. Early strategic advice can help businesses identify regulatory exposure, structure transactions more effectively, avoid unrealistic completion timetables and reduce the risk of disruption after signing or completion.

In an environment where regulatory intervention can occur long after a deal appears complete, merger control analysis is increasingly becoming a core part of transaction strategy rather than simply a technical regulatory consideration.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.