The Competition and Markets Authority (the CMA), the UK’s competition law watchdog, continues to take a strong interest in the construction industry.

The sector has been under scrutiny for decades and this has resulted in numerous companies being investigated and fined for participating in a variety of anti-competitive practices.

Examples have included colluding to fix future prices, exchanging commercially sensitive information, carving up geographic markets, allocating customers and rigging bids for contracts. A broad range of players in the construction sector have been impacted, including ready mixed concrete; aggregate; flat roofing; roofing materials, groundworks products, demolition and asbestos removal to name but a few.

The CMA’s interest in the sector remains as strong as ever as illustrated by its recent announcement that it is widening its ongoing investigation into suspected bid rigging for roofing contracts for schools funded by the government’s Condition Improvement Fund (“CIF”). This has now been extended to other public and private sector bodies.

The CMA has now helpfully given the sector a steer on the sorts of activities to avoid when interacting with competitors. Guidance was published at the end of 2025, following its decision to fine 10 UK construction companies for rigging bids for demolition and asbestos removal contracts at numerous sites in the UK, including Selfridges in London, Oxford University and the Metropolitan Police Training College. The companies were fined a total of £60 million for rigging bids for 19 contracts worth over £150 million and 4 directors were disqualified for 4 years.

In that case, the companies colluded to submit proposals that were designed to lose the tender by putting forward a bid that was deliberately high or deliberately offering a poorer service. In addition, some of the companies involved who were the chosen “losers” of the contracts were offered compensation by the winner. This behaviour is always viewed as a serious restriction on competition as it distorts genuine competition between competitors and typically results in higher pricing, lack of choice and stifles innovation, all to the detriment of the consumer.

The following is a useful summary of the CMA’s guidance. Although addressed to the construction sector, this has some useful takeaways for all other sectors.

Lessons Learned

“The Don’ts”

• Never agree with a competitor to submit or alter a bid to lose a tender so that a rival can “win”.
• Never accept compensation for letting a rival “win” a tender.
• Do not fix future prices with competitors or exchange other commercially sensitive information as to future conduct.
• Do not share markets - “We will keep out of Scotland if you keep out of England” or “We will not approach customer A if you keep away from customer B”.

Such behaviour will inevitably result in companies being heavily fined and individuals could also be prosecuted for cartel offences or disqualified as directors for their personal involvement.

The Dos

• Put some basic competition law compliance training into place, particularly for your sales teams. This will help you demonstrate that you are taking competition law seriously and may help put you on a good footing if you receive an approach from the CMA in future.
• Ensure that company directors and senior personnel have been briefed on the risks of failure to comply with competition law. Company directors now have a personal responsibility for ensuring that companies comply with competition law and failure to do so may result in director disqualification and personal prosecution.
• Make use of the CMA’s leniency programme if there are any concerns about being implicated in a cartel or other anti-competitive behaviour. The benefits can be substantial. If a company is the first party to report being party to illegal conduct before the CMA launches an investigation and co-operates fully with the CMA, it may benefit from full immunity from any fines, and its employees and directors can also avoid criminal prosecution and director disqualification. Examples include the total immunity given to Virgin Atlantic when it blew the whistle on its price fixing arrangements with BA on fuel surcharges. Virgin Atlantic got full immunity whilst BA was fined £58.5 million. Sky UK was also given full immunity from fines for reporting numerous instances of exchanging commercially sensitive information about freelancer pay in the TV production sector.
• Businesses can still benefit from a reduction in fines after an investigation has commenced if they can add value to the CMA’s investigation. A recent example of this was the 40% reduction in a fine imposed on JD Sports for its participation in price fixing and exchanging commercially sensitive information with competitors on the sale of Rangers strips and kits. JD was able to give the CMA more information which allowed the CMA to uncover other illegal activity.  The leniency programme was updated last year to clarify that total immunity will now only be given to applicants who apply before an investigation has commenced.
• If you have been adversely affected by anti- competitive behaviour, whether a cartel or abuse of market power, make full use of the process available to report this to the CMA. 

The construction sector is likely to remain under close scrutiny for the foreseeable future, and this guidance should give companies a helpful steer on how to avoid any unwelcome approaches from the CMA.