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Guidance

Whistleblowing to the CMA

You can report wrongdoing to us in confidence. Find out what to expect when you contact us.

From:
Competition and Markets Authority
Published:
2 October 2026

Have you seen something at work that concerns you?

The Competition and Markets Authority (CMA) is a ‘prescribed person’, which means you may qualify for whistleblowing protection if you tell us about your employer (or ex-employer) possibly breaking competition or consumer protection law.

You can contact us online, by phone or by email. If you contact us, we will listen to you carefully and handle your information sensitively, so as to protect your identity from disclosure.

You do not have to know everything or be certain that the behaviour is illegal. Just tell us what you already know. The information you share could lead us to investigate and take enforcement action.

If you’re thinking about whistleblowing to us, you might have questions about what you need to do.

Who can make a whistleblowing report

You can report to the CMA as a whistleblower if you:

  • learned about the suspected wrongdoing through your current or previous work
  • reasonably believe that the wrongdoing concerns competition or consumer protection law and that the information you are giving us is substantially true, and
  • reasonably believe that raising the wrongdoing is in the public interest, for example because it affects other people

If you are a worker and make a whistleblowing report, you may qualify for legal protection under whistleblowing law. Under these protections, you should not be treated badly by your employer or lose your job just because you’ve spoken out in this way, and a non-disclosure agreement (sometimes called a confidentiality or ‘gagging’ clause) cannot be used to stop you making a whistleblowing report.

The CMA cannot give you legal advice, nor can we decide whether or not a whistleblower qualifies for protection. Contact another organisation (such as Protect or Citizens Advice) to understand your position, or consider finding independent legal advice.

If you aren’t a whistleblower but still want to tell the CMA about something, there are other ways to report a problem.

What you can report as a whistleblower

You can tell the CMA about your employer or ex-employer:

  • entering into anti-competitive arrangements with other businesses; such as agreeing prices, or sharing confidential, commercially sensitive information
  • abusing a dominant position in a market
  • failing to follow a legal requirement imposed by the CMA
  • breaking consumer protection law
  • hiding evidence of this behaviour

You can report wrongdoing that relates to any area of our work, such as mergers, consumer protection, competition enforcement (such as cartels and other types of anti-competitive behaviour), and digital markets.

We do not deal with:

  • individual complaints from consumers, about such things as poor customer service or faulty goods
  • other matters of fraud (such as scams) or serious fraud (such as bribery or corruption)
  • personal employment or workplace issues, including health and safety
  • product safety, counterfeit and illegal items, age restricted sales, or rogue traders

If we cannot deal with your report, check whether another organisation can help you.

When to make a report

You can call the CMA before deciding whether to make a full report, if you want to discuss your concerns or understand your options.

You can make a report about something that is happening now, or something that happened in the past.

The sooner you tell us about what you think is wrong, the clearer your recollection is likely to be and the better the information you’re likely to give.

How to make a report

Before you make a report

If you’re unsure about your legal protections, or want to discuss your situation before you make a report, consider finding independent legal advice, or contacting Protect or Citizens Advice.

Preparing your report

Don’t try to investigate and gather information you do not already have. Just tell us what you already know. You don’t have to know everything, but try to tell us:

  • what happened
  • when and where it happened
  • who or what was affected
  • how long it lasted
  • who was involved
  • how you know about it

Provide any information you already have that could be relevant (for example, screenshots, emails or documents).

What happens when you contact us

Whichever way you contact us, we will:

  • review the information you share carefully, and ask for more information if we need it
  • discuss any concerns you have about confidentiality

If you call us, we’ll ask you to leave a recorded message. If you leave your contact details, we’ll call you back to discuss your concerns further.

If you email us, you will receive an initial automatic reply confirming receipt. We will review your information and, if you have provided contact details, respond within 5 working days.

Remaining anonymous

You can report to us anonymously. If you do not provide contact details, we will still review the information you share but we cannot discuss your concerns or next steps with you, and it may limit our ability to act on your information.

When completing our online form, you can choose whether or not to provide personal details.

Contact us

  • Telephone: 020 3738 6556

Find out about call charges

What happens after you make a report

We will keep your information secure, and your identity will be known only to a small number of essential CMA staff. We will handle your details and the information you provide sensitively and in confidence. In particular, we will do everything we can to protect your identity.

We follow data protection law carefully when handling your personal information. Read our personal information charter to find out more.

Once you’ve made a report, we will conduct any necessary research and assess the information alongside existing intelligence the CMA may hold on the business or sector. Then we’ll decide what to do next.

The CMA must make efficient and effective use of its resources. When deciding what to investigate, we consider our prioritisation principles.

We might decide to:

  • investigate businesses or people we suspect have broken competition or consumer protection law
  • warn businesses that their conduct may breach competition or consumer protection law, and ask them to review their practices
  • investigate or study a market where there may be competition or consumer concerns

Alternatively, we might decide not to do anything or suggest you contact another enforcement agency instead.

We cannot always keep you informed about what we plan to do, particularly where doing so could prejudice an existing or future investigation.

Who else you can report to

If the CMA cannot help you, you can report to another ‘prescribed person’ instead. For example, contact:

Check the full list of other people and bodies you can report to. 

Find more information 

Watch Tony O’Sullivan, the CMA’s Director of Intelligence and Investigations, and Elizabeth Gardiner, Joint Chief Executive at Protect, talk about how the CMA works with whistleblowers and handles their information in confidence. 

Whistleblowing: support, confidentiality and speaking up

Find data on the number of whistleblowing disclosures made to the CMA in each financial year.

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