Over the years there have been different styles of number plates. As the DVLA run out of combinations, they decide on a new scheme.

The recent formats

For 42 years we have had 'dated' number plates - where the year of release was shown by either a prefix letter or a suffix letter:

  ABC 1A   for the first 21 years (21 years, not 26 because Q, U, I, Z and O are not released as prefix letters, although Q is issued to any cars that have been greatly modified from their original specification. it isnt a standard prefix/suffix).

  A1 ABC   for the next 21 years up to and including March 2001

The last two letters (i.e. BC in the above example) were based around the area of the country the plate was issued in with the first letter of the three letter block and the numbers (1 - 999) being sequential in their release. When issuing numbers, the DVLA decided to keep certain numeric combinations back from general release. Initially numbers 1 - 20 were kept back but then when they got further into the alphabet they kept more and more back from general release, to include numbers like 22, 30, 33,40,44 etc and 111,200,222 etc and then finally other numbers like 123 and 321. This has actually made it relatively easy to offer these plates for sale because we know that all 1-20's for all letter combinations were kept back for selling along with certain other numbers, and all the rest were either allocated to be used on cars or allocated to be auctioned if they were very nice numbers like 

  S1 MON     or   P1 LOT   etc.

The older formats

Further back than 42 years ago, the number plates were not dated - plates were just a series of letters and numbers either numbers then letters or letters then numbers,

examples being   56 ABC   or   A 1300  

this style, being much older tends to be more expensive but adds a certain class to any car.

The brand new format

In September 2001 a new system was introduced that will last us for 50 years. This consists of 2 letters, 2 numbers and 3 further letters, giving the most letters ever available on a British number plate

- i.e.   BD51 ABC   .

The first 2 letters represent the area from which the car was first registered (if the number was assigned to the car by the garage selling the car). The next 2 numbers are the year identifier - 51 (the current number) means September 2001. 02 will mean March 2002, 52 will mean September 2002, 03 will mean March 2003 etc. So basically if the number is less than 50 it was released in March so you need to add 2000 to the number to get the year of release and if it is higher than 50 it was a September release and you need to add 1950 to the number to get the year of release. (1950 + 51 = 2001, 2000 + 02 = 2002).

Because there are no 'number ranges' for the DVLA to withhold for sale, it has been very difficult recently to categorise what numbers are available for sale and which have been allocated for use by car dealerships for new cars. Because of this, all anybody can generally offer is a facility for you to request your desired number and we will confirm availability or suggest other alternatives.

The rule on assigning numbers to cars is that you cannot make an older car look newer, so you can't have a car that was released in 1989 and put a year 2000 based X registered plate on it because it gives the effect of the car looking newer - however you can make cars look older, so the older style dateless numbers can go on pretty much any car nowadays and something like J1 STU can go onto a new car without problems.