Registration plates are attached to the front or back of most road vehicles (the obvious exception being bicycles). Usually made of acryllic¹ and measuring 524mm x 112mm² they display a series of letters and numbers unique to each vehicle. Different countries have different systems for allocating the sequence of letters/numbers and in mainland Great Britain³ this is the responsibility of the DVLA⁴. Areas off the mainland, N.Ireland, The Channel Islands and the Isle of Man have their own systems - the Isle of Wight does not. They are also referred to as "Number Plates", a "Vehicle Index" or in the USA "License Plates".

An interesting feature of the British number plate is that the front one has black letters on a white reflective background, while the back plate is a yellow reflective background. It is a legal requirement that the letters and numbers are of a specific size (50mm) on a reflective material. The font may not be customised e.g. italicised and the plate must be kept readable (i.e. clean) otherwise owners can be fined.

Why have them?

Car registration plates are a way of identifying different cars. Imagine that you had just seen a little old lady knocked down on a pedestrian crossing. Without a registration plate, you'd only be able to tell the police that it was a blue Ford Escort desperately in need of a wash. How much time would it take the police to find and questions all the owners of said make, model and colour car. With a registration plate you need only say the car was, say, R572 FGB. A quick look on the police computer and the boys in blue can be round the culprits house in double-quick time.

How are the numbers/letters ordered?

One of the more exciting⁵ facts about the plates is that they usually allow you to identify the age of a car. This is not always the case if a car has to be reregistered or a personalised plate is transferred.

The registration system has evolved since its introduction in 1904 and different formats for ordering the number and letters have been used as the number of vehicles on the road has grown and combinations have run out. The system applies to about 99% of vehicles, but exceptions can be found.

Early registrations

The first registration system was introduced in 1904 and had 1 or 2 letters followed by up to four numbers e.g. x 9999or xx 9999. The letter codes represented the place of origin, for example A represented Greater London and EL represented Bournemouth. The complete list of area codes are provided by a website that also holds useful information on the pre-1963 years.

Dateless British Marks

When the one and two letter combinations ran out an extra letter was added to the start of the plate and the format, now referred to as Dateless British Marks, became xxx 999. When areas ran out of combinations they simply reversed the order of number and letters to give the Reversed Dateless British Marks format of 999 xxx.

Suffix system

In January 1963 the Suffix format started to be used by some areas and from 1965 it became a legal requirement. The sequence became xxx 999x where the final letter represented the year the car was registered.

Therefore vhehicles with a plate ending "A" e.g. ABC 123A had been registered during 1963. Jan 1964 began the "B" registrations, '65 - "C", '66 - "D" and '67 - "E".

There were though very few "E" registration plates in circulation as it was decided that the registration month should be moved to August. Therefore "F" plates are for cars registered Aug 1967 through to July '68. The system continued on⁶ missing out "I", "O", "Q", "U" and "Z" due to the possibility of mistaking them for the numbers 1, 0 and 2 and the letter V. These letters were still used in the initial 3 letter part though.

Prefix System

The Prefix system was introduced in August 1983 and follows the format x999 xxx. It was during this system that allocating representing area codes via the 2nd and 3rd letters ended. Plates continued to be issued every year with August seeing the introduction of a new letter.⁷.

Once again letters "I", "O", "U" and "Z" were missed out, but "Q" was reserved for special cases. "Q" plates indicate a vehicle that's age cannot be confirmed, usually these are either imported from abroad or specially built e.g. kit-cars or converted lawnmowers.

With the suffix or prefix indicating the year a car had been first registered, the new plates issued each August became quite a status symbol. As a result of this people considering buying a car in June or July would wait until August so that they could have the new letter to display to their neighbours. For the car industry this created problems with peak sales being confined to one month of the year, rather than spread evenly throughout. To counteract this new plates started to be issued every 6 months - in March and September.

Therefore "S" plates became the first cars to be registered in September 1998 with "T" plates being issued in March 1999 and the system continuing⁸ through to "Y" in March 2001.

Current system

From September 2001, the order of letters and numbers became xx99 xxx. In a return to area coding, the first two letters identify where the car was registered, the numbers represent the date of registration and the final three letters are random.

Personalised Number Plates

Not all combinations of letters and numbers are issued on number plates. One of their great fascinations is that if the numbers and letters are put in certain orders they can make words! Some times rude words, for example OBO 110X can be moved around to make O BO11OX!! With the great 80s era of capitalism and people trying to outdo each other it became a great status symbol to have a plate with your name on it e.g. C1LLA, J1MMY.

Sometimes though people have names with letters that look nothing like a number and they try to force them. For example using an 8 or 3 as an E almost works, but a 7 for an A - no chance. Bad luck M7RK N.

The market for personalised plates has now reached a stage where the vehicle licensing authorities run a computer programmes before each registartion period. This programme identifies plates that may have significance to people and they are not issued as part of the normal registration procedure. Instead an auction for these plates is held and people will pay thousands of pounds for them.

International Recognition

In addition to a registration plate, many cars also display a small ovoid sticker containing 2 letters indicating their country of origin e.g. GB - Great Britain. Since March 2001 it has been legal for owners to use a number plate that has the European Union flag followed by the 2 letter country identifier on the left side, preceding the actual registration.