Government Telephone Preference Scheme
The Government Telephone Preference Scheme (GTPS) is a British system for limiting outgoing calls from landlines if the network is overloaded during an emergency. Numbers registered under the GTPS will still be able to make outgoing calls if the service is limited. All telephones will still be able to receive calls.
There are three categories of use - the most essential are called Preference Category I, and are limited to 2% of lines of a telephone exchange. According to a British government document they are intended to be limited to "lines vital to the prosecution of war and to national survival". The second category - Preference Category II - are for lines needed for the community and these and Preference Category II are limited in total to 10% of the exchange. All other users are in Category III.[1]
The scheme was established in the 1950s.[2] The scheme is now (2013) closed to addition of new numbers due to the replacement by service providers of the infrastructure over which the scheme operated.[3] A date for the full closure of the scheme has not been publicly set.
Phones on the scheme include armed forces headquarters, local authority emergency planning centres, emergency services such as police, fire and ambulance and public telephone boxes. Since 1992 the United Kingdom Warning and Monitoring Organisation and Royal Observer Corps operational lines have been deleted from the scheme.
A similar scheme limiting mobile telephone access is called MTPAS (formerly ACCOLC).
The GTPS should not be confused with the Telephone Preference Service which is an opt out telephone list funded by the British direct marketing industry.[4]