United Kingdom licence plate suffix/prefix systems
Until 1963, the suffix/prefix systems of numbering didn’t exist, but by beginning of the 1960s, many County Councils (who were then responsible for the registration of vehicles) were running out of combinations based on the original numbering system, which called for up to 3 letters and up to 3 numbers, or 2 letters and 4 numbers. Either the letters or the numbers could come first. Each Council had its own unique series of letters, so you could always tell which County a car had originally been registered in.
From 1st January 1963, many (but not all) Councils started using the suffix system; 3 letters, up to 3 numbers, and a suffix letter which would change annually on 1st January each year. Logically enough, they began with A. Some Councils with smaller car populations didn’t adopt the suffix system until 1965, when the suffix letter was C.
1963=A (but not everywhere)
1964=B (more councils, but still not everywhere)
In response to the motor industry’s requirement for a stimulant to improve slow sales during the summer months, the government decided that the annual plate change should occur on 1st August of each year. So;
1 Jan 1967-31 Jul 1967=E
1 Aug 1967-31 Jul 1968=F
and so on, from 1 Aug in one year until 31 July in the following year
The letters I, O, Q, U and Z were not used, I and O because of the risk of confusion with numbers, Q because it simply isn’t used (or wasn’t; more about Q later), U because it would look too much like V which would have succeeded it, and Z because it is exclusive to Northern Ireland.
From 1 October 1974, responsibility for the registration of vehicles passed from the County Councils to a new central authority, the DVLC (Driver and Vehicle Licensing Centre). Since then, the registration number is not always an accurate guide to the area in which a vehicle was first registered.
Because the suffix system was now exhausted, the prefix system began in 1983, i.e. prefix letter, followed by up to 3 numbers, followed by 3 letters. It used the same 1 Aug-31 July changeover as the suffix system
had used, and the same letters were omitted (except Q, but see below):
But the motor industry had now decided that it didn’t like the annual plate change after all, because it forced too many new car sales into one month, so the government decreed a new system from 1999;
1 Aug 1998-28 Feb 1999=S
1 Mar 1999-31 Aug 1999=T
1 Sep 1999-28 Feb 2000=V
1 Mar 2000-31 Aug 2000=W
1 Sep 2000-28 Feb 2001=X
1 Mar 2002-31 Aug 2001=Y
From 1 September 2001, a new system started. The format is:
2 letters the “Local Memory Tag”
2 numbers the “Age Identifier”
3 letters the “Random Element”
I.e. AB 12 CDE
The two letter local memory tag is linked to the particular local registration office responsible for the area in which the vehicle is first registered. A list of local memory tags can be found at
The age identifier changes every six months, as per the previous prefix system. It works as follows.
1 Sep 2001-28 Feb 2002=51
1 Mar 2002-31 Aug 2002=02.
1 Sep 2002-28 Feb 2003=52
1 Mar 2003-31 Aug 2003=03
1 Sep 2003-29 Feb 2004=53
1 Mar 2004-31 Aug 2004=04
1 Sep 2004-28 Feb 2005=54
1 Mar 2005-31 Aug 2005=05
1 Sep 2005-28 Feb 2006=55
1 Mar 2006-31 Aug 2006=06
1 Sep 2006-28 Feb 2007=56
1 Mar 2007-31 Aug 2007=07
1 Sep 2007-29 Feb 2008=57
1 Mar 2008-31 Aug 2008=08
1 Sep 2008-28 Feb 2009=58
1 Mar 2009-31 Aug 2009=09
1 Sep 2009-28 Feb 2010=59
1 Mar 2010-31 Aug 2010=10
1 Sep 2010-28 Feb 2011=60
1 Mar 2011-31 Aug 2011=11
1 Sep 2011-28 Feb 2012=61
1 Mar 2012-31 Aug 2012=12
The pattern will continue until all the permutations are exhausted, which should be somewhere around 28 Feb 2050=99.
The random element is simply three letters issued at random, and is unique to each vehicle. The letters I and Q will not be used, but Z will, for the first time in mainland UK registrations. Combinations which might be considered offensive will not be issued.
A word about Q. Since 1 Aug 1983, any car which is imported from abroad and whose age cannot be determined, or which is assembled from major parts the majority of which are not new at the time of assembly and which originated from more than one vehicle, will be registered with a number bearing a Q prefix. Thus some kit-cars, and interestingly some London taxis which have been assembled from bits of other scrapped London taxis have Q-plates.
One further thing I ought to mention is the matter of “cherished” registration numbers. It’s possible to transfer your registration number from one vehicle to another, if it is of special significance to you.
So, whilst it is unlikely that someone would wish to retain a pretty meaningless number such as J247 CYP, other numbers such as H12 DEE (spaced H1 2 DEE), or SCA 1N (spaced S CA1N), or M1 SSY (spaced M1SSY), will probably be retained by their owners and switched from one car to the next. Of course, these numbers are comparatively rare, particularly in classic car circles where a dating registration number is just a part of the car’s originality. The rules governing these numbers state that they cannot be used in a way that would make a vehicle look younger than it actually is; e.g. the aforementioned M1 SSY could be used on a car first registered any time after 1st August 1994, but not on one registered before that date.
Largely based on a posting by Leroy Curtis in newsgroup ‘alt.binaries.pictures.autos’