Technical specifications for number plates in UK
All motor vehicles using British roads are required by law to display number plates containing registration marks provided by the DVLA. Exact styles and specification for the number plates (including personalised number plates) are outlined in the BS AU 145e, the new BSI standard which was introduced on 28 February 2018, in accordance with the Road Vehicles (Display of Registration Marks) Regulations 2001.
The primary specifications itemised in the standard include:
• Number plate material
The standard did not specify the base material for the manufacturing process. However, it does require the material to meet photometric requirement, and must have a plain finish with no watermarks. However, a large majority of manufacturers today only use acrylic to manufacture number plates owing to the material’s retroreflective properties. Acrylic plates are also known for their durability against extreme weather, damaging ultraviolet rays and moisture.
• Plate Size and Dimension
BSI’s standard also did not specify the exact size and dimension of number plates for UK roads. However, market pressure has more or less set the dimensions of the plates here to approximately 520mm by 110 mm, mirroring other Western European nations.
Colour contrast is important for the optical character recognition (OCR) software of the automatic number plate recognition (ANPR) cameras to work accurately. As such, more than ever, correct colour combinations are very important. Two background colours are used for number plates: plain white for front plates, and plain yellow for rear plates. The alphanumeric combination on the plate, meanwhile, must be solid black. Under the previous standard (BS AU 145d), 3D, carbon and hi line styles were permitted; it is no longer the case now.
• Typeface/ Font
Only one typeface is permitted on number plates - Charles Wright 2001. It is absolutely prohibited to use the font in bold, italic and cursive styles as it could affect OCR efficiency.
• Font size
With the exception of the number ‘1’ and letter ‘I’, all alphanumeric characters must be 89mm tall and 64mm wide, and the stroke width must be exactly 16mm. Spacing between each character is 13mm. To compensate for the narrowness of the number ‘1’ and letter ‘I’, layouts must visually these characters to be inside a 79mm by 50mm block.
For the supplier name and postcode at the bottom of the plate, the height must be no taller than 10mm and no shorter than 3mm. The BSI certification, BS AU 145e, which is located on the bottom right hand corner, must also comply with these dimensions.
The small lip area below the rectangular border (8mm thickness) is left to the discretion of the manufacturers. However, any lettering must still use the Charles Wright 2001 font.
• Plate Display Location
All four wheeled vehicles (bus, SUVs, lorries, etc.) are required to display number plates centrally at the front and rear of the vehicles. Owing to space limitation, motorcycles and three wheeled vehicles are not required to display a rear number plate.
• National Flags
The Euro/GB acronym and flags on the left flap of the number plates must be pre-printed and a part of retroreflective finish. Flag stickers cannot be pasted on the plate.
Please note that existing number plates for vehicles registered before 1 September 2001 are not required to follow the specifications above. However, if their number plates were damaged or stolen, replacement plates must follow the new specifications.
Failure to adhere to the above specifications could lead to fines of up to £1,000. Repeated infractions could eventually lead to withdrawal of vehicle registration.