Our summary
The OECD published this updated version of its bid rigging guidelines in September 2025. Bid rigging happens when companies that should compete for a public contract secretly agree on who will win or at what price. The guidelines explain the main forms of this collusion and the market conditions that make it easier, such as few suppliers or very similar products. They also cover how public bodies can work together against it, how to design tenders that keep competition strong, and how to report suspicions to the competition authority. The update supports the OECD Recommendation on Fighting Bid Rigging in Public Procurement (OECD-LEGAL-0396).
The main audience is public officials who plan and run procurement. The principles are general, so each organisation can adapt them to its own buying process. The report includes a tender design checklist and a bid-rigging detection list, and the full report can be read online on the OECD website.
How auditors use it: Internal auditors and fraud examiners can use the detection list as a set of red flags when they test procurement files, for example by looking at bid patterns, prices and the history of winners. The tender design checklist helps auditors judge whether procurement procedures reduce collusion risk. It is also a good reference when auditors recommend better controls or decide when to pass a case to the competition authority.