Know which phone you can rely on.

999, 112 and 18000 must not be relied on from a new account whose outbound service is held. Use another working phone for emergency assistance. An account, payment, delivered handset or incoming call does not prove emergency calling works.

Temporary preview systems are inbound-only and are not for emergency calls. Never make a test call to an emergency number yourself.

Provide the physical address where the number is used, including enough detail to identify the premises. A billing address, registered office or handset delivery address is not automatically the right service location.

Tell us before moving a number or using it at a different location. The address must be verified and lodged through the carrier's process; saving it in a form alone does not complete that process.

Internet calling depends on working power, connectivity and equipment. A power cut or loss of internet can prevent a call, including an emergency call. Plan an alternative that will work for your circumstances.

A phone used away from its registered location can give an inaccurate location. When contacting emergency services, explain where help is needed rather than assuming an account address describes your current position.

Tell the emergency operator your current location verbally. Emergency calls carried over the public internet may not receive the same network priority or quality assurance as calls on a mobile network or a traditional circuit-switched fixed line. Tell us if you will use the service at more than one location so that nomadic use can be recorded.

Moving your number can remove the existing service you use for emergency calls. Agree an alternative and the timing of the change before the port request is submitted.

Outbound activation follows confirmed payment, successful provisioning and the emergency acceptance checks for website-created accounts. The tracker must distinguish an address awaiting verification from an active service.

• Numbers and porting
• Contact support