Competing fairly

Report a business cartel


A business cartel is an agreement (whether written, oral or both) between competing businesses that does one or more of the following:

  • fixes prices
  • rigs bids (tenders)
  • establishes output restrictions or quotas
  • shares or divides markets

Cartels seriously damage other businesses and the economy and consumers end up paying inflated prices or receiving lower quality goods and services. One of the priorities of the Competition and Markets Authority (CMA) is to act against cartels.

Report a cartel to the CMA

Cartels are illegal under both civil and criminal law. The CMA encourages anyone who has seen cartel activity to report it. Call the cartels hotline on Tel:  020 3738 6888 or Email:  Alternatively, fill out the online reporting form. Take action against cartels and if the information you provide leads to an investigation, you may earn a financial reward.

For more information, see the CMA Stop Cartels website. 

You may already have information that would be useful to the CMA. This should be reported to the CMA. You should also contact the CMA for advice before trying to obtain any further evidence of cartel activity. The CMA will be able to tell you if they would like you to take any further action and, if so, how to reduce any risks you may face. They can also advise you of the sorts of information that may be relevant to any investigation.

The CMA will take steps to ensure that the information you provide is safeguarded and handled with a view to protecting your identity from disclosure.

Cartels are generally conducted in secret and they can be hard to detect and prove, which is why the CMA may offer financial rewards for information. This information can help to detect, investigate and fine businesses that have been involved in cartel conduct. It can also help prosecute the people involved. 

The CMA also offers leniency to businesses reporting cartels that they are themselves involved in.