What is a URN (Unique Reference Number)?

A URN is the reference a police force issues to a specific monitored alarm system at a specific address, which lets the Alarm Receiving Centre pass activations from that system to the police. It belongs to the address and the police force, not to you or your installer, and it can be suspended or withdrawn if the system generates too many false calls.

The URN is the mechanism by which the police agree, in advance, to treat signals from one particular system as worth acting on. It is issued by the force covering the address, against an application from an approved installer or ARC — you cannot apply for one directly.

Forces usually charge for issuing a URN and for its annual maintenance, and those fees are set locally, so they differ from force to force. Expect the cost to be passed through in your monitoring contract.

Crucially, a URN carries conditions. Excessive false activations can get it suspended, and continued problems can get it withdrawn, at which point police response stops until the system is fixed and the URN reinstated. Because the URN attaches to the address, a history of false alarms at a property can follow it.

If you move house, the URN does not come with you. A new address needs a new application.