This document, NSI Technical Bulletin No. 0040, provides guidance on the implementation of PD 6662:2017, which supersedes the previous PD 6662:2010 standard for intrusion and hold-up alarm systems in the UK. It outlines the requirements for the design, installation, commissioning, and maintenance of these systems, referencing relevant British and European standards. The bulletin emphasizes that compliance with PD 6662:2017 is mandatory for companies seeking NSI approval and details the transition period for existing and applicant companies to align with the new standards by June 1, 2019. Manual review may be needed for complete details on specific changes and requirements.