From DVLA
Colour and dimensions[edit]
Black number plates with white or silver characters are permitted on vehicles registered before 1 January 1973. This vehicle was registered in Truro.
The front plate of a vehicle registered in County Down.
Number plates must be displayed in accordance with The Road Vehicles (Display of Registration Marks) Regulations 2001.
All vehicles manufactured after 1 January 1973 must display number plates of reflex-reflecting material, white at the front and yellow at the rear, with black characters. This type of reflecting plate was permitted as an option from 1968: many vehicles first registered before 1973 may therefore carry the white/yellow reflective plates and, where they were first registered during or after 1968, they may have carried such plates since new.
In addition, characters on number plates purchased from 1 September 2001 must use a mandatory typeface and conform to set specifications as to width, height, stroke, spacing, and margins. The physical characteristics of the number plates are set out in British Standard BS AU 145d, which specifies visibility, strength, and reflectivity.[1]
Number plates with smaller characters are only permitted on imported vehicles, and then only if they do not have European Community Whole Vehicle Type Approval and their construction/design cannot accommodate standard size number plates.[1]
The industry standard size front number plate is 520 mm ? 111 mm (20?" ? 4?"). Rear plates are either the same size, or 285 mm ? 203 mm (approx 11"x8") or 533 mm ? 152 mm (approx 21"x6"). There is no specified legal size for a number plate. For example, the rear number plate of a Rover 75 is 635 mm x 175 mm.
The material of UK number plates must either comply with British Standard BS AU 145d,[2] which states BSI number plates must be marked on the plate with the BSI logo and the name and postcode of the manufacturer and the supplier of the plates or
"(b) any other relevant standard or specification recognised for use in an EEA State and which, when in use, offers a performance equivalent to that offered by a plate complying with the British Standard specification, and which, in either case, is marked with the number (or such other information as is necessary to permit identification) of that standard or specification."
as specified in
http://www.legislation.gov.uk/uksi/2001 ... ule/2/made The Road Vehicles (Display of Registration Marks) Regulations 2001 (Statutory Instrument 2001 Number 561), Schedule 2.
Older British plates had white, grey or silver characters on a black background. This style of plate was phased out in 1972, and is now legal to be carried only on vehicles first registered before 1 January 1973. A vehicle which was first registered on or after 1st January 1973 shall be treated as if it was first registered before that date if it was constructed before 1st January 1973 (as specified in
http://www.legislation.gov.uk/uksi/2001/561/made PART IV MISCELLANEOUS).
Motorcycles formerly had to display a front plate, which was usually but not always a double-sided plate on top of the front mudguard, curved to follow the contour of the wheel and visible from the sides. The requirement for the front number plate was dropped in 1975 because of the severe danger these presented to pedestrians in the event of a collision. Motorcycles registered after 1 September 2001 may only display a rear number plate, while motorcycles registered before that date can display a number plate at the front if desired. From January 1973 onwards, the front plate is white and the rear plate is yellow.
Specialist HM Forces vehicles use non reflective black plates with white lettering. This is because in combat, the reflective plate can be used for targeting by laser guided weapons. The UK forces use a completely different system of numbering.