Current style number plate format

Area code
The area code, also known as the local memory tag is made up of the first 2 letters of the registration and signifies the local DVLA (Driver & Vehicle Licensing Agency) registration office to issue the number plate. The first character is known as the mnemonic, and represents a broad area where the registration office was located with the second character representing the actual registering office within that region.
All DVLA local offices (with the exception of DVLA Swansea) where shut by December 2013, however the letters still represent the respective regions. The letters I, Q and Z cannot be used in the first 2 characters.
Age identifier
The area code is then followed by a two-digit age identifier which changes twice a year, in March and in September. Registrations issued 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, and 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; so a vehicle registered on 10 January 2019 would be issued with the number “68” as the age identifier.
Three letter sequence
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 identifier (the initial four characters).
Like the area code, the letters I and Q are restricted and cannot be used in the last three letters, however the character “Z” is allowed.
When will the format change again?
The current system should have sufficient numbers to run until 28 February 2051.