In the United Kingdom all motor vehicles that are over three years old have to undergo an annual vehicle inspection, known as the Ministry of Transport, or MOT, test. The MOT test is designed to ensure that a vehicle complies with ministry regulations regarding road worthiness and safety. Vehicle registration plates, known as number plates, fixed to the front and rear of cars, and to the rear of motorcycles, must conform to department regulations.
Checks Made During The MOT Test
Number plates of all vehicles are checked during a MOT test, including those of motorcycles and light goods vehicles, such as vans. MOT inspectors check to see that the number plates are present and show the correct registration for the vehicle. The vehicle registration maps to the vehicle's make, model, colour and vehicle inspection number, all of which are held in the Driver and Vehicle Licensing Agency database. The inspectors make a visual check to ensure that number plates are not damaged or obscured, which may happen, for example, if a towing ball is fitted to the rear of a vehicle. Although it is a legal requirement that number plates supplied after 1 September 2001 should also contain the name and postcode of the registration plate supplier, this is not part of the MOT check.
Number Plates Supplied After 1 September 2001
All number plates supplied after 1 September 2001 must conform to British Standard BS AU 145d. Cars must carry number plates at the front and the rear, and front plates must consist of black letters and numbers on a white background, while rear registration plates must consist of black letters and numbers on a yellow background.
For cars manufactured after 1 January 1973, the regulations state that number plate characters must be 79mm high and 50mm wide. The stroke of a character is a single element of a character, such as the straight line forming the left side of an upper-case letter "P." The stroke width for characters on a number plate must be 50mm. The margins between the characters on a number plate and the edge of the number plate must be 11mm, and there must be an 11mm space between the characters in a group. Where there are two groups of characters on a number plate, the space between the groups must be 33mm.
Number Plates of Cars Manufactured Before 1 January 1973
Cars built before 1 January 1973 may display number plates that conform to the standard that was in place up until that date. These number plates consisted of a black background with letters and numbers coloured white, silver or grey, displayed on both the front and the rear of the car. Cars can display either a "Group 1" number plate, or a "Group 2" number plate, and the dimensions for characters and spaces differ for each group. Mixing dimensions from each group on the same number plate is not allowed.
Group 1 number plates must have characters that are 89mm in height and 64mm in width. The stroke of the characters must be 16mm, and the space between characters must be 13mm.
Group 2 number plate characters should be 79mm high and 57mm wide, with a stroke of 14mm. (reference 2)