Report businesses that you think are acting in an anti-competitive way to the Competition and Markets Authority (CMA).
Fill in the form to report anti-competitive practices and send it to firstname.lastname@example.org.
You can also call the CMA to make a report.
CMA enquiries centre
0203 738 6000
You can report concerns about anti-competitive behaviour in certain sectors to an industry authority. These are:
- Civil Aviation Authority for airports and air traffic services
- Ofcom for television, radio, telephone, postal and internet services
- Ofgem for gas and electricity in England, Wales and Scotland
- Office of Rail Regulation for railways in England, Wales and Scotland
Types of anti-competitive behaviour
Anti-competitive agreements can include price-fixing, limiting production to drive up prices, agreeing not to sell to a competitor's customers.
These agreements can be formal or informal and may include 'shared understandings','concerted practices' or 'gentleman's agreements' where businesses cooperate or act together.
You should also report businesses that abuse a dominant market position - eg by offering unfair prices to customers or suppliers, refusing to supply, or limiting production.
Report a cartel
A cartel is an agreement between businesses about not competing with each other - eg by price-fixing, bid-rigging, output quotas or restrictions, or market-sharing arrangements. Cartels are usually secret.
CMA cartels hotline
Telephone: 0800 085 1664 or 020 3738 6888
Read the guide cartels and the Competition Act for more information.
You may be treated with leniency if you report a cartel you've been involved with.
Businesses may be fined up to 10% of their worldwide turnover if they enter into an anti-competitive agreement or abuse a dominant market position.
You may be fined or sent to prison for up to 5 years if you are involved in cartel activity. Company directors may be disqualified from being a director for up to 15 years.