The decision to exclude an economic operator from participation in a public procurement procedure is a serious one. The impact on the economic operator is potentially significant. The inappropriate exclusion of an economic operator can also adversely affect competition and have an impact on value-for-money outcomes for the contracting authority. SIGMA Brief 24 focuses on the issue of whether it is permitted under EU law to use an official automatic exclusion list for reasons related to prior contract performance, especially in the light of the newest judgements of the Court of Justice of the European Union (case C 465/11). In the context of the Brief, the term “official automatic exclusion list” means a centrally administered and published list of economic operators that are excluded from tendering for public procurement contracts.