Guidance

Cartels: come forward and apply for leniency

How to report your involvement in a cartel under our leniency programme and what to expect.

The Competition and Markets Authority (CMA) investigates businesses and individuals involved in cartel activity. Our leniency policy helps us detect and act against cartels. This page sets out how you can come forward and apply for leniency.

What is a cartel?

A cartel is when 2 or more rival businesses agree to act together instead of competing. For example, businesses might agree what prices they are going to charge or divide a market so they are sheltered from competition. This kind of cheating can take many forms – it could involve arrangements that are formal or informal, verbal or in writing.

Cartels benefit their members but they also:

  • harm customers, consumers and other businesses
  • damage the wider economy

Cartels are illegal and there are serious consequences if you are caught in one. Businesses can be fined and barred from public sector contracts, directors can be disqualified and individuals criminally convicted.

Report a cartel you know about

If you are not involved in a cartel but know about one, report it to us. You could get a reward of up to £250,000 for information that leads to an investigation.

Why apply for leniency

Leniency is when you tell the CMA about your involvement in a cartel and cooperate with our investigation. In return, you could receive protection from the consequences (as explained below). Both businesses and individuals can apply for leniency.

There are different types of leniency. The type available will generally depend on:

  • whether or not any other individuals or businesses involved in the cartel have already applied for leniency
  • whether or not the CMA is already investigating the cartel
  • whether you are applying for leniency as a business or an individual

Being the first to apply for leniency before the CMA has started to investigate is the only way to get guaranteed immunity from:

  • financial penalties
  • director disqualification
  • criminal prosecution
  • public contract exclusion and debarment

For more information about the different types of leniency and the protection they offer, read our full leniency guidance, short guide for businesses and short guide for individuals.

Applying for leniency

Call the CMA’s leniency enquiry line on 020 3738 6833 to ask if leniency is available, and, if so, to apply.

In order to get immunity or leniency you must:

  • stop participating in the cartel
  • provide us with all the information, documents and evidence you have about the cartel
  • cooperate with us throughout the application process and any investigation we carry out
  • admit involvement in the cartel (this normally takes place later in the investigation process, usually just before the CMA issues a statement of objections)

Consider getting legal advice if you think you have been involved in cartel activity. You may qualify for free legal advice through the Competition Pro Bono Scheme

You can also ask the CMA for confidential guidance by calling our leniency enquiry line on 020 3738 6833. You do not have to disclose your identity.

For more information about making an application, read our short guides or our full leniency guidance.

Cartel activity in Scotland

If the cartel activity has taken place wholly or partly in Scotland, it is for the CMA to decide whether to grant leniency to businesses. However, we cannot give guaranteed immunity to individuals for criminal offences that are to be prosecuted in Scotland.

For more information about the handling of leniency applications involving cartel activity in Scotland, read the short guide for individuals and the full leniency guidance.

Updates to this page

Published 31 March 2014
Last updated 28 October 2025 show all updates
  1. Guidance updated to reflect changes to the CMA's leniency policy and processes.

  2. First published.

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