The current vehicle registration mark (VRM) format in Great Britain was introduced on 1 September 2001. Read from left to right, the number plate identifies where and when a vehicle was registered.
The first 2 letters otherwise known as the local memory tag or area code signify the local DVLA (Driver & Vehicle Licensing Agency) registration office. All DVLA local offices where shut by December 2013 however the letters still represent the region. The letters I, Q and Z cannot be used in the first 2 characters.
The first character (mnemonic) represents a broad area where the registration office was located with the second character representing the actual registering office within the region.
The first 2 letters are then followed by a two-digit age identifier which changes twice a year, in March and in September. Registrations registered between 1 March – 31 August use the the last two digits of the year they are registered in e.g a vehicle registered on 6 March 2018 would use “18” as the age identifier. For vehicles registered between 1 September and 28 February in the subsequent year, 50 is added to the previous age identifier (18 + 50 = 68) value e.g a vehicle registered on 10 January 2019 would use “68” as the age identifier.
To complete the number plate, a random three-letter sequence is added to the end which uniquely distinguishes every vehicle sharing the the same area, office and age initial four character sequence. The letters I and Q are not used in the last three letters however the character “Z” is allowed.
The current system should have sufficient numbers to run until 28 February 2051.