A market study or market investigation lets the CMA examine how a whole market works, not just the conduct of a single firm, and impose remedies where competition is not working well. The regime sits in Part 4 of the Enterprise Act 2002 and has been strengthened by the Digital Markets, Competition and Consumers Act 2024. For a business in a market under scrutiny, an investigation can lead to binding orders that reshape how it operates, so early and informed engagement matters. We advise businesses responding to a study or investigation, and those affected by its outcome.

The regulatory framework

The Part 4 regime works in two stages. A market study is the CMA’s initial examination, carried out on a twelve-month statutory timetable from the launch notice under section 130A, and can end in no action, undertakings, or a reference to a fuller inquiry. A market investigation is that fuller inquiry, conducted by an independent CMA group over eighteen months, extendable once by up to six months. To make a reference the CMA needs only reasonable grounds for suspecting that features of a market harm competition (section 131); the full finding of an adverse effect on competition is made by the group at the end of the investigation (section 134).

The concept of a “feature of a market” is broad. It covers the structure of the market, the conduct of suppliers or acquirers, and the conduct of customers, and it does not require any intention to harm competition. That breadth makes the regime well suited to digital and platform markets, where the concern is often structural, such as network effects or customer inertia, rather than a specific act of misconduct. The DMCC Act 2024 sharpened the tools available: the CMA can now make targeted references confined to particular features, accept undertakings at any stage, trial remedies before imposing them, and is under a formal duty to keep remedies under review and act where they prove ineffective.

What is the difference between a market study and a market investigation?

The two stages differ in who conducts them, how long they take and what they can deliver. The table below sets out the distinction.

Feature	Market study	Market investigation
Who conducts it	The CMA as a single authority	An independent CMA group
Statutory timetable	Twelve months from the launch notice	Eighteen months, extendable by up to six
Threshold	Reasonable grounds for suspecting harmful features	A full adverse effect on competition finding
Outcome	No action, undertakings, or a reference	Binding remedies: orders and undertakings

What remedies can a market investigation impose?

At the end of an investigation the CMA can impose remedies to achieve, in the words of section 138, as comprehensive a solution as is reasonable and practicable to the adverse effect on competition it has found. The toolkit spans behavioural remedies, such as conduct restrictions, information disclosure, price controls and access requirements, and structural remedies up to divestiture or the separation of a business. Structural remedies are the most intrusive and the CMA generally prefers behavioural measures where they can do the job. During an investigation the CMA can also make interim orders to stop parties taking pre-emptive action, and can require the reversal of steps already taken.

Why market investigations matter for your business

A market investigation can reshape a market on an industry-wide basis, binding every significant participant, not just a firm accused of wrongdoing. The consequences can be far-reaching, from mandated access and price controls to divestiture, and the remedies now come with an ongoing review duty that keeps businesses exposed for years after the report. The DMCC Act’s ability to trial remedies before imposing them, and to accept undertakings at any stage, also creates real opportunities to shape the outcome for a business that engages constructively and early. The regime is a core CMA tool that sits alongside the digital markets regime: the CMA can run a market study or investigation in parallel with, or instead of, work under the strategic market status regime, particularly in markets that are not designated. Understanding where a study is heading, and what a workable remedy looks like from the inside, is central to protecting a business’s position.

How we work

We work with clients in three ways: as direct legal advisers on a specific question, as specialist co-counsel alongside a competition or corporate team, and as fractional general counsel on a retained basis. Rob Bratby currently holds four fractional General Counsel appointments, at The One Touch Switching Company, TelXL, Core Communication and the UK Payments Initiative, giving direct insight into how businesses experience regulatory scrutiny and what a workable remedy looks like operationally. A one-year secondment to Oftel adds first-hand experience of how a regulator frames a market inquiry. Where a matter involves personal data, we address it through our data protection practice.

Frequently asked questions about market investigations

What triggers a market study?

The CMA can open a market study where it has concerns about how a market is working, drawn from complaints, super-complaints, its own intelligence or the outcome of other cases. A study is an examination, not an accusation against a particular firm, and it runs to a twelve-month statutory timetable from the launch notice.

Does a market investigation require proof that a firm broke the law?

No. The regime targets features of a market that harm competition, whether structural or conduct-based, and does not require any intention to harm competition or any breach of a prohibition. That is what distinguishes it from enforcement under the Competition Act 1998, which addresses specific unlawful conduct.

Can the CMA force a company to sell part of its business?

Yes. Structural remedies, including divestiture, are available under Schedule 8 of the Enterprise Act 2002. They are the most intrusive option, and the CMA generally prefers behavioural remedies where these can achieve a comprehensive solution to the adverse effect on competition it has found.

How does this regime relate to the digital markets regime?

They are complementary. The market investigations regime applies to any market, while the strategic market status regime under the DMCC Act 2024 applies only to designated digital firms. The CMA can use a market study or investigation in markets that are not designated, or alongside its digital markets work, and the DMCC Act strengthened the Part 4 toolkit.

How should my business respond to a market study?

Constructively and early. A market study is an information-gathering exercise, and the quality of a business’s evidence and engagement shapes whether the CMA refers the market, accepts undertakings or takes no action. Because the DMCC Act 2024 lets the CMA accept undertakings at any stage and trial remedies before imposing them, there is real scope to influence the outcome for a business that engages early with a clear account of how the market works and what a workable remedy would look like.

Also see

Explore our related Digital Regulation pages on SMS Designation and Conduct Requirements, Pro-Competition Interventions, Merger Control in Digital Markets and Competition Enforcement and Litigation, or return to the Digital Regulation hub. The regime intersects with our work in Telecoms Regulation, Payments Regulation and Data Protection. For commentary on current developments, see our Insights.