Vehicle registration plates (commonly referred to as "number plates" in British English) are the alphanumeric plates used to display the registration mark of a vehicle, and have existed in the United Kingdom since 1904. It is compulsory for motor vehicles used on public roads to display vehicle registration plates, with the exception of vehicles of the reigning monarch used on official business.
The Motor Car Act 1903, which came into force on 1 January 1904, required all motor vehicles to be entered on an official vehicle register, and to carry alphanumeric plates. The Act was passed in order that vehicles could be easily traced in the event of an accident, contravention of the law or any other incident. Vehicle registration alphanumeric plates in the UK are rectangular or square in shape, with the exact permitted dimensions of the plate and its lettering set down in law. Front plates are white, rear plates are yellow.
Within the UK itself, there are two systems: one for Great Britain, whose current format dates from 2001, and another for Northern Ireland, which is similar to the original 1904 system. Both systems are administered by the Driver and Vehicle Licensing Agency (DVLA) in Swansea. Until July 2014, Northern Ireland's system was administered by the Driver and Vehicle Agency (DVA) in Coleraine, which had the same status as the DVLA. Other schemes relating to the UK are also listed below. The international vehicle registration code for the United Kingdom is UK. Prior to 28 September 2021, it was GB. The specification of plates incorporating the UK code was created by the British Number Plate Manufacturers Association, and is seen as the default design by the Department for Transport.
Standard requirements
Number plates must be displayed in accordance with the Road Vehicles (Display of Registration Marks) Regulations 2001.
Number plates must be made of reflex-reflecting material, white at the front and yellow at the rear, with black characters. This was first required on all vehicles manufactured after 1 January 1973, having been optional before then. Subsequently, the requirement was modified by the Finance Act 2014, to allow any vehicles registered within the 'historic vehicles' tax class to use the older style pre-1973 black number plates. This rule applied on a 40-year exemption basis, and until 2021 rolled forward automatically each year on 1 April to include vehicles manufactured before the first of January forty years prior. A change was introduced on 1 January 2021 that will permit only vehicles dating prior to 1 January 1980 to use the old style pre-1973 black and silver number plates.
The post-1973 type of reflecting plate were permitted as an option from 1968: many older vehicles 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. Many buses delivered to London Transport between 1973 and the mid-1980s continued to bear white-on-black plates. This was also true of some other bus operators, though only on the rear end in most instances; Reading Transport was one other operator which persisted with black front plates into the 1980s.
Characters on number plates purchased from 1 September 2001 do not use a specific named typeface, but must use what is known as the "prescribed font" within legislation set out in The Road Vehicles (Display of Registration Marks) Regulations 2001. One such example of a typeface adhering to this prescribed font is Mandatory, a variation of the frequently used Charles Wright typeface. However, the wording in the legislation designates that slight variations in typeface are legal providing they are "substantially similar" to the prescribed font.
Characters must also 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 145e (formerly BS AU 145d until 31 August 2021), which specifies visibility, strength, and reflectivity.
Number plates with smaller characters meeting standards for motorcycles 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, for example vehicles made for the US or Japanese market may only have a 305mm x 152mm (12" x 6") area to affix a number plate in which a standard one line plate is too long (460mm) to fit whilst a two line plates is too tall (199mm).