The laws covering UK number plates has been constantly evolving since being introduced, mainly to stop criminal activity regarding stolen or fake plates and to cope with the ever increasing cars on the road.

Back in 1903 when they were introduced, registration numbers were based solely on location and followed the style “A 1″ through to “YY 9999″. This continued until 1932 when the numbers began to run out as the popularity of cars increased although the new format still used location. The new number plates used the sytem of “A A A 1″ to “YYY 999″, excluding the letters I, Q and Z. There were also some three letter combinations that were never issued – for instance, the last two letters of the Great Yarmouth registration was “EX” but plates issued in this region were never allowed to use “SEX”, which resulted in many droll headlines such as “No Sex for Great Yarmouth Motorists.” In 1963, when the numbers were once again on the verge of running out, an additional letter was added on to the end of plates all around the country, which corresponded to the year that the car was registered.

The next change came in 1973, but this was a change of style rather than a change of format. Previously, number plates were either white on black or silver on black, and were made from pressed metal or plastic characters attached to the metal plate. No laws were in place regarding size, font or gap between characters but this all changed in the beginning of 1973. From then on, characters on number plates had to be 89mm by 64mm or 79 by 57mm. The gaps between characters were also standardised to be 13mm with the larger characters and 11mm with the smaller.

The next change was once again to the format and saw the letter that identified the year being moved from the end of the registration to the beginning. This format remained in place until September 2001 when the current style of plate introduced a two-letter area code, followed by a two-number year code, followed by three random letters. The reasoning behind this was that the first four characters would be easy to remember and would allow police to drastically reduce the number of potential vehicles involved in a crime if witnesses could remember just the first four digits, or even just the first two. It also meant that second-hand buyers could have some clue as to the age of the car, and solved the problem of numbers running out until 2051.

To ensure that all format and style regulations are observed, every supplier of number plates must be registered with the DVLA, and the name and postcode of the supplier is displayed on every license plate they make and issue. Those buying registration plates must also supply proof of identity, as well as the documentation to show the number plate is theirs. Suppliers must also keep records of all of the above information and make those records available to the police when required.