Every Security Officer must be licenced for manned guarding activities which are defined as: Security Guarding, Keyholding, Cash and Valuables in Transit, Close Protection, Door Supervision, Public Space CCTV Surveillance. In Northern Ireland it also includes Immobilisation, Restriction and Removal of Vehicles (Vehicle Immobilisation).
Licensing requires private security operatives are properly trained and qualified. You can ask any operative from an NSI approved company (providing a service listed above) to show you their licence if it is not clearly visible when they are working at your home.
Note: Alarm system installers are not required to hold an SIA licence.