Biometric technologies have advanced considerably over the past decade, and have paved the way for more widespread use by governments, commercial enterprises and, more recently, by the consumer through the introduction of sensors and apps on mobile phones. This report provides introductory information about the application of these technologies to achieve secure recognition of individuals by organisations which form part of critical infrastructures in the EU. As a specific example, it offers guidance about the implementation of physical access control systems using biometric technologies. It is principally addressed at managers and security officers within these organisations. With the information in this report, managers and officers should be in a better position to discuss their specific requirements with technology suppliers, specialist systems integrators and consultants – and therefore lead to applications which are more secure without compromising on their usability. The report emphasises the importance of considering the effectiveness of the entire application – and not just focussing on the performance of the biometric subsystem. Note that the representation of specific devices does not imply any recommendation by the authors or the European Commission.