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Detecting and deterring bid rigging

Bid-rigging is a serious type of anti-competitive activity. It can drive up the prices of contracts for vital goods or services and deny purchasers from getting true value for money.

 CMA Competition and Markets Authority

Bid-rigging is a form of cartel – businesses collude when tendering for contracts, driving up the price for the winning bidder. 

It removes the incentive for companies to compete to win a contract, which in turn means purchasers do not get true value for money.

Evidence suggests that cartels often result in overcharges of 10% to 20% (and more), costing taxpayers millions of pounds.

Procurement and supply professionals need to know where and how bid-rigging can occur during a tender process.

Tools to help you

The Competition and Markets Authority (CMA) has developed tools and advice to help purchasers within the public sector detect suspicious activity and avoid becoming victims of bid-rigging. These include: 

How to report it

If you suspect a business of engaging in illegal cartel behaviour, such as bid-rigging, this should be reported to the CMA.

Contact the cartels hotline on 020 3738 6888 or email


CMA Bid Rigging Advice for Public Sector Procurers

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