This practical guidance relates to the Procurement Act 2023 regimeThis Practice Note provides an introduction to special regime contracts under the Procurement Act 2023 (PA 2023), ie concession contracts, defence and security contracts, light touch contracts, utilities contracts and below-threshold contracts. New in-scope procurements must be carried out under PA 2023. For background reading on the PA 2023 regime, see Practice Note: Introduction to the Procurement Act 2023—PA 2023.Procurements started before PA 2023 came into force (on 24 February 2025) remain governed by the previous legislation (the Public Contracts Regulations 2015, SI 2015/102, the Utilities Contracts Regulations 2016, SI 2016/274, the Concession Contracts Regulations 2016, SI 2016/273, and the Defence and Security Public Contracts Regulations 2011, SI 2011/1848).This practical guidance focusses on public procurement under PA 2023. For background reading on the key differences between PA 2023 and the previous regime, see Checklist: Procurement Act 2023—key changes. For details of the transitional arrangements, see Practice Note: Procurement