This Practice Note examines the different types of performance security documents which are used on construction projects in the UK. It provides brief commentary on parent company guarantees, bonds (including performance bonds, advance payment bonds and retention bonds), collateral warranties, third-party rights, direct agreements and letters of reliance. It also considers provisions within construction contracts that provide performance security, such as payment security methods and performance guarantees. Parent company guarantees Parent company guarantees (PCGs) are often provided to an employer by a main contractor’s holding or parent company. In essence, if the main contractor defaults in its obligations under the construction contract, then the employer can seek recourse against the holding/parent company either financially or potentially in terms of performance if the parent company has sufficient resources to step in and continue the carrying out of the project in the main contractor’s stead. Theoretically, this recourse could also be used in the event that the main contractor is insolvent, although employers should bear in mind that the insolvency of a main contractor will affect the contractor group