CMA highlights bid-rigging risk in public procurement markets

On 8 September 2026, the UK’s Competition and Markets Authority (“CMA”) published two reports highlighting the risk of bid-rigging in public procurement markets, encouraging public authorities to use AI-powered bid-rigging intelligence tools to identify suspicious patterns of bidding behaviour suggestive of bid rigging. 

The two reports, Public Procurement in the National Interest: Reflections from the CMA and Rigged Bids, Real Costs: A Case for Urgent Action on Bid Rigging in UK Public Procurement, are part of a wider outreach exercise by the CMA to support the economic growth, recognising that one of Government’s most powerful tools for supporting economic growth, innovation, and resilience is through its public procurement activity. 

Competitive procurement markets deliver better outcomes

Bid rigging typically occurs when suppliers collude to prevent a procurer from obtaining goods or services at a competitive price. It can take several forms, including:

• Cover bidding: competitors agreeing to submit dummy bids, giving the false impression of genuine competition;
• Bid suppression: competitors agreeing not to submit bids; and
• Bid rotation: competitors agreeing to take turns to be the predetermined winner.

Regardless of the form, bid rigging increases prices above competitive levels, reduces the quality of goods and services, and weakens incentives to innovate. Research suggests typical price increases of between 10-20%, which may reach as high as 80%. There are even real-world examples indicating increases in road traffic accidents and hospital mortality rates related to the adverse effect on quality associated with bid rigging.

Construction and defence procurement specifically being called out

Public procurement markets are prone to bid-rigging, there often being relatively few suppliers capable of bidding for the higher value more strategic contracts.  The CMA suggests that construction contracts and defence supply contracts are most at risk. However, the problem is seen by the CMA as pervasive throughout public procurement markets more generally; empirical research suggesting that one third of observed procurement contracts featured patterns suggestive of collusion. 

Use of AI-driven tools to identify suspicious bidding patterns

The problem is that the detection of bid rigging has often been reliant on traditional means such as whistleblowers, leniency applications, and the reporting of red flags. Though the CMA recognises the value of these methods, it also recognises their limits. 

The CMA is now working with a number of central Government departments to deploy AI-powered tools to bidding data, data which is increasingly available with the introduction of the Procurement Act 2023.  The CMA has already developed the bid-rigging intelligence tool (BRIT), an AI tool which scans and analyses tender information to identify patterns suggestive of bid rigging. The CMA has been running pilots of this tool with Government departments, including the Department for Work and Pensions, Department for Education, and Ministry of Justice, and it is looking to engage with the Ministry of Defence on defence procurement given the increase commitments in this sector. 

The data being used is focussed on losing-bid data, gathered in a consistent, machine-readable format and the CMA is advocating for centralised data collection. It acknowledges the costs associated with such a programme, but it argues that the benefits of detecting bid-rigging – decreased costs and increased quality and innovation – justify these costs. 

What does this mean for procuring authorities?

• The CMA is asking procuring authorities to consider engaging with its data screening pilot. If this is successful and there is political will, data collection obligations, particularly the gathering of losing bid data, will make these tools potentially very powerful.  This would be a continuation of the trend brought in through the Procurement Act 2023 to centralise the collection of data through the updated Find-A-Tender service platform.
• Procurers should also consider how to build procurement processes which are resistant to bid rigging and may wish to introduce training for individuals to detect relevant red flags.

What does this mean for suppliers / bidders?

• Suppliers will need to double-down on compliance. These initiatives increase detection risk, exposing suppliers to lengthy competition law investigations and fines of up to 10% of worldwide turnover, director disqualifications, and even criminal prosecutions under the cartel offence.                                                         
• For those suppliers reliant on winning public sector contracts, there is also the further risk under the of debarment from public procurements under the new regime introduced under the Procurement Act 2023.

For more information on managing competition compliance risk in public procurement markets, please reach out to a member of the CMS Competition team.