UK CMA Updates and Consolidates Guidance on Its Wide-Reaching Markets Regime

On 3 February 2026, the Competition and Markets Authority (“CMA”) published new consolidated guidance on its markets regime, following a consultation last year. The new guidance, which consolidates six previous documents into one, reflects changes to the CMA’s powers made by the Digital Markets, Competition and Consumers Act 2024 (“DMCCA”) and the CMA’s widely publicised commitment to greater pace, predictability, proportionality, and process (known as the “4Ps”). 

Key changes include:

• The CMA will have the power to appoint new “expert panels” to inform its markets work, which could significantly impact on the mix of evidence available to the CMA.

• “Roadmaps” will now be published at the start of all markets work (but are subject to change as the project progresses), setting out the anticipated timetable, key milestones, opportunities for engagement with the decision-makers and whether the CMA plans to appoint an expert panel.

• The CMA will conduct regular internal “state of play” meetings to check that the scope of their work remains appropriate. Parties will not be invited, but will receive updates in the form of an email, a progress report or potentially a meeting. Generally there will be earlier and more frequent engagement with parties.

• Working papers, detailing the CMA’s analysis on emerging issues, will no longer be systematically published, but interim reports will be published earlier in the process.

• The CMA has expanded powers to accept remedies in lieu of launching (or finishing) a full market investigation, a potentially valuable way to avoid or cut short a long-duration investigation (as introduced in the DMCCA).

• The CMA has new powers to trial information remedies alongside alternative remedy designs, which may increase the effectiveness of outcomes but will be an additional burden on parties.

• The CMA also has new powers to remove outdated or ineffective remedies and include “sunset clauses” to bring new remedies to an end after 10 years. This should avoid perpetuating the current long tail of old, burdensome remedies. The CMA is already currently consulting on removing around 60% of in-force remedies that are no longer needed.

Many of these changes mirror changes to the CMA’s mergers regime. While increases in transparency and flexibility are strongly welcome (especially in relation to remedies), the move to more informal engagement and reduced sharing of emerging analysis may reduce opportunities for market participants to formally engage with the CMA’s thinking.

The new guidance will apply immediately: i.e., to all markets work that commences after 3 February 2026. Significant reforms to the markets regime are currently being consulted on by the Department of Business and Trade—which include the collapse of the two-phase process into a single unitary review. However, these reforms will require primary legislation and are unlikely to be in effect for some years. The new guidance concerns the regime as it presently stands. Further updated guidance will be needed once the new regime comes into force.

Context: the CMA’s markets regime

A powerful toolbox for intervention

Relatively uniquely amongst major global antitrust agencies, the CMA can investigate a whole market to identify whether the conditions of competition are working well, or a specific feature or combination of features across a number of markets, without investigating other aspects of competition in those markets. The regime does not require any illegality or infringing conduct. 

Currently, the UK markets regime has three levels of “market project”: (1) a non-statutory market review, typically used by the CMA to develop its understanding of a market; (2) a Phase 1 market study, examining whether a market is working well for consumers (up to 12 months in duration); and (3) a Phase 2 in-depth market investigation to assess whether features of the market are having an adverse effect on competition (18 to 24 months in duration plus 6 to 10 months for implementing remedies).

Remedies under the markets regime can be wide ranging, from behavioural requirements such as improving consumer information, to government recommendations on improving regulation of the market concerns, to (following a full market investigation) divestments that can significantly restructure the whole market (as occurred in 2011 with the break-up of the former BAA airports by the then Competition Commission).

In some ways, a much-admired regime

The UK markets regime stands out for being one of the longest standing and furthest reaching. In June 2020, the European Commission consulted on introducing similar powers—known as the “new competition tool”—but the lack of a robust legal basis in the EU treaties for such broad intervention without any infringement meant that the initiative was abandoned. More focused ex ante powers were instead created for digital markets specifically under the Digital Markets Act. A number of countries have market regimes broadly similar to the UK, including Denmark, Germany, Greece, Iceland, Italy and South Africa, while others have more limited regimes (without remedy powers) including Austria, Belgium and Bulgaria.

More recently, the CMA has made a point of conducting much faster markets work, with an emphasis on “cost of living” priorities, including 12-month market studies into Infant Formula and Road Fuel (the latter resulting in the creation of an app to check local fuel prices and a legal obligation on suppliers to provide data for the app). In addition to plans for a review of dental services, the CMA also used its general market review powers to call for evidence in relation to the development of generative AI markets (in parallel with reviewing a number of AI partnerships to check for merger control jurisdiction under its merger powers).

In other ways, a much-criticised regime

Notwithstanding its admirers, the variable effectiveness for consumers and the heavy burden on business of the UK markets regime have been heavily criticised. The Retail Banking market study and subsequent investigation (2013 to 2017) resulted in burdensome requirements on retail banks to implement “open banking” flows of consumer data (often credited with powering the growth of the UK fintech sector and which have since inspired wider “open data” initiatives). However, the package of remedies agreed following the Energy market investigation (2014 to 2016) attracted criticism around the apparent mismatch between the scale of the problem and the weakness of the remedies, which were aimed at increasing customer switching despite evidence pointing towards weak customer engagement as the main issue.

Engaging with a potentially years-long, very detailed process also creates a significant demand on management time and resources. The current Veterinary Services market investigation—which could have resulted in structural remedies because market concentration concerns were a driver in launching the investigation—is considered to have adversely impacted valuations of businesses under scrutiny. Recent market investigations into Cloud Services (2022 to 2025) and Mobile browsers and cloud gaming (2023 to 2025) both ended in adverse findings, but recommended that remedial action should be taken under the CMA’s new DMCCA digital market regulation powers—requiring market participants to undergo a further investigation to reach a conclusion.

Key changes in the revised, consolidated guidance

Anticipating the government’s markets regime legislative reforms: new expert panels

Under the UK government’s plans to reform the markets regime, the current two-phase process will be combined into a single unitary review, and the decision maker for a Phase 2 market investigation will no longer be a panel of independent (part time) members, but a group mainly comprising CMA executives and independent non-CMA-staff experts. The influence of this planned future change can already be seen in the guidance in the introduction of “expert panels”.

• Expert panels: Expert panels have not been a feature of the current regime. However, the guidance refers to the possibility of the CMA appointing expert panels with sector expertise for a market review, market study, or a full market investigation. Expert panels will be appointed for a particular market project with their role and engagement with the CMA determined on a case-by-case basis. The guidance emphasises that input from the expert panel will be considered alongside other sources of evidence but also notes that the CMA will attach evidential weight according to whether it is provided by a subject matter expert or someone with knowledge or experience of the market under review.

Procedural reforms: greater transparency, but with trade-offs

• Project roadmaps: The CMA will set out a “project roadmap” at the start of each market review, study, or investigation, covering the anticipated timetable, key milestones, opportunities for parties’ engagement with the decision-makers, and an indication of whether an expert panel will be appointed. While this will create better visibility into the process from the outset, enabling better resource planning, the CMA remains free to change the roadmap as its review develops—potentially counteracting any early-stage benefits.

• Internal review meetings: The CMA will hold internal “state of play” meetings during market studies and investigations to assess whether the scope of the case remains appropriate and whether any lines of inquiry should be dropped. Businesses will receive updates following these meetings, which might be in the form of an email, a progress report or an “external” state of play meeting. Clearly, the value to the parties of this change will depend on the quality and depth of those updates. However, this development should also help case teams to sharpen the focus of their investigations early on, reducing unnecessary work for both the CMA and market participants.

• Earlier engagement: The new guidance encourages earlier and more frequent engagement with affected parties, including webinars, “teach-in” sessions, informal calls, and progress reports. More informal engagement should improve transparency—similar changes have been positive under the CMA’s mergers regime—but the expectation of enhanced engagement may increase the burden on businesses, particularly smaller market participants who are already resource constrained.

• Removal of working papers: The CMA will stop routinely publishing detailed “working papers” setting out analysis of the core issues being considered and instead publish these by exception (e.g. where it is exploring a novel, complex or technical issue or where its views about evidence or its likely conclusions fundamentally change). Working papers were previously key in understanding the CMA’s emerging thinking and gave parties the opportunity to formally respond, so this change is significant. In particular, the proposed informal alternatives (i.e. calls, progress reports, and state of play updates) may not provide parties with the same degree of detail for effective engagement in written responses and at hearings.

• Earlier interim reports: The CMA has committed to publishing its interim report earlier in the investigation process. This should, in principle, provide earlier clarity on the CMA’s direction of travel. However, there is a risk that speed comes at the expense of rigour. If the CMA has not had sufficient time to consider all the evidence and conduct economic analysis/test the analysis presented to it before publishing an interim report, there is a greater chance that its provisional conclusions will change. This could result, contrary to the intention, in greater uncertainty for businesses and the wider market. This has been a challenge in some cases under the CMA’s new Phase II mergers procedure; with less time for economic work before interim reports are published.

New remedies powers and policies

• Undertakings in lieu of a reference or report: The new guidance reflects DMCCA reforms to make it easier to accept undertakings following a market study, in lieu of making a full market investigation reference. The DMCCA has also opened up the timeframe for accepting undertakings in lieu so that they can also be discussed and accepted during the course of a market investigation. There are only three past examples of undertakings in lieu of a market investigation being accepted (two from 2005 concerning remedies to open up competition in postal franking machines and to address BT’s vertical integration in wholesale and retail telecoms markets, as well as a third in 2012 to improve competition for extended warranties on domestic electrical goods). Expanding the scope of undertakings in lieu is therefore a welcome development and may enable some or all aspects of a market investigation to be closed early.

• Trialling information remedies: As noted, many market investigations have ended in measures to reduce information asymmetries and increase information available to consumers to make informed choices or facilitate switching. However, the effectiveness of information remedies can be difficult to evaluate. The DMCCA gave the CMA new powers to conduct formal trials of different remedy design options before deciding on the final remedy package. This is a sensible development in principle, although it will clearly add time to the overall process and there is a risk that the demands of concurrent trials cause a significant burden on parties.

• Power to amend ineffective remedies and include a “sunset clause” for new ones: The DMCCA also gave the CMA power to amend or remove remedies that are found to be ineffective (in addition to the power to remove or amend remedies where there has been a change of circumstances). Combined with the Guidance’s push for default “sunset clauses” for new remedies, this is a welcome mechanism for addressing remedies that are no longer working and is a precursor to the Government’s more recent proposal for standard 10-year remedy caps in its proposed legislative reforms.

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