How the DoT categorise number plates & Car registrations

The DoT number plates system

Number plates were first issued with a format of one letter, one number, the issued was A1 by London CC in 1903. The following format comprised of two letters and four numbers. This series was replaced as and when they were exhausted. So, whilst Liverpool's series KA lasted for two years between 1925 and 1927, the series SJ was still being issued by Bute Council in 1963.

By the mid 1930s, the two letter four number series of number plates were totally exhausted in some areas, and new three letter three number series were introduced. AAA 1 to AAA 999 was first issued by Hampshire CC in 1934 and the commencement of the BAA series in 1936. This continued until the mid 1950s when plates were reversed to three numbers three letters.
Between 1963 and 1965 different councils started to issue "suffix" plates, three letter three numbers and a year suffix. The registration year ran from 1 January - 31 to December until 1967, when the suffix change was moved to 1 August.

a) 1 or 2 letters, followed by 1 to 4 digits, e.g. A1 and DY 4832
b) 3 letters, followed by 1 to 3 digits, e.g. TXN 476
c) 1 to 4 digits, followed by 1 or 2 letters, e.g. 20 D and 1164 CX
d) 1 to 3 digits, followed by 3 letters, e.g. 166 KVD
e) 3 letters, 1 to 3 digits, and a year letter, e.g. GEY 309E
f) a year letter, 1 to 3 digits, and 3 letters, e.g. J21 YTB

Year letters for DoT registrations began with A suffix in July 1963, and originally changed each January, becoming compulsory for all areas from the beginning of C suffix in January 1965. E lasted only from January to July 1967 : thereafter the year letter changed (as now) each August. By 1983 DoT year suffixes had been exhausted with the end of Y suffix (I, O, U and Z were not used); year prefixes were then begun as in (f) above.

It is currently understood that DoT number plates as from March 1999 will change every 6 months instead of 12, and will occur in March and September. This would mean that T to Y prefix would last only 6 months each, and a new system would be required in September 2001, assuming the same letters are used as were first time round.

Just as the above helps us to tell the age of a vehicle, most DoT number plates will of course also tell us the area where the vehicle was issued with that number. In 1903 all the existing Counties, County Boroughs (and Scottish Burghs of over 50,000 population) were instructed to register all vehicles in their area, and were issued with a one or two letter code, those in England and Wales in order of size (from A for London to Y for Somerset, and AA for Hampshire to FP for Rutland). Scotland had mainly S combination number plates, and Ireland (then including the south) had Is and Zs; both were allocated alphabetically, first counties then towns. As for each allocated code the digits reached 9999, new codes were allocated as required, likewise to new County Boroughs and Burghs as they were created. In 1963 XA to XY were taken away from London, and subsequently reallocated. Many of the surviving number plates from this time and earlier have now been transferred onto newer vehicles as so-called "cherished numbers".

More information on DoT number plates

With local government reorganisation in the seventies all these issuing authorities disappeared, and the issue of registrations was transferred to the DoT computer at Swansea. The actual business of issuing new registrations was now done by 81 regional offices, currently called Vehicle Registration Offices (VRO). The 2 letter combinations (marks) were allocated to the VROs, largely based on the old authorities (above) in their area. Some VROs have since been closed, and their marks often continued to be issued by neighbouring VROs.

So what does the registration newsletter (RNL) cover in all this ? For non-year letter formats we track the highest number issued for each local authority, and the extent of all known gaps. For each year letter, suffix and prefix, we track for each authority or VRO what three-letter combinations were used with that year letter, and what were the lowest and highest numbers issued. The most significant gaps are (a) when non-year letter issues finished (b) between the end of each year letter and the beginning of the next, where often several three letter combinations (trios) in the sequence are left unused. As well as registering new vehicles, VROs regularly need to issue fresh registrations to used vehicles. These must receive a number with the year letter which applied when they were new : the progress of these "re-registrations" is tracked by RNL, and they often begin to fill in the year-end gaps. The coverage in RNL is a mixture of summaries and lists of all the latest known advances.

DoT tax discs are also a useful source of information. As well as usually confirming the registration (in cases of plate errors), a first tax disc (as distinct from the subsequent ones issued by a post office) when issued by a VRO can tell us which one issued it, from a computer-printed code in the range 301-399. A new move in the past few years has been Automated Registration and First Licensing (AFRL). Increasingly new cars are registered by the dealer using a computer link with DoT (via the manufacturer), so the VRO is not involved, although the letters used will still indicate the area of origin. AFRL registrations can be identified from the original tax disc, which carries a stamp with the word "dealer" and a 4 digit code, which identifies the dealer.

Some year prefix registrations are not generally covered by RNL, because they don't follow rules such as the above. This applies to most of them with digits between 1 and 20, and for H prefix onwards any whose digits are multiples of 10, 100 or 111; also for H and R prefixes, certain digits which DoT identify as matching car model numbers of the time e.g. 106, 325, and 911. These all come under DoT's Custom or Select schemes, where the public can obtain by phone registrations of their choice, provided they are not already taken. Because the letters and numbers are purely the owner's choice, there is no pattern, so nothing for RNL to track. We do however list the (usually) previously unissued cherishable registrations which are sold at most DoT auctions.

Other types of DoT plates in common use

Diplomatic. Apart from some specials, generally with the digit "1" and often with no year letter, most UK diplomatic issues comprise three digits identifying the foreign embassy, mission or body, then D (for accredited diplomats) or X (for other personnel), followed by a serial of three digits. RNL tracks the highest digits known for each initial three digit code. A few year letter marks with trio RXS were once used.

Exports to EU countries. Special issues began with K prefix, are identified by ending in XP, confined to trios AXP to MXP which show the month of issue : each calendar year A for January through to M for December. Only issued by a handful of VROs, and it appears each one is allocated a block of digits each month. The VRO can be determined from the tax disc or more usually the make of vehicle.

Age Related (Non Year Letter). Theses are the only non-letter marks now being issued, apart from at auctions and a few specials. These are confined to, and compulsory for, vehicles made before 1963 (when year letters began) and arise because all vehicles reregistered since 1983 have had to be given a registration appropriate to their age. For those new before 1963 (originally 1956) the format is three letters followed by three digits, from series previously never used, in the range ASV-YSV, CSU-YSU, BSK-YSK, GVS-YVS, TYJ-YYJ, KFF-YFF, MFO-YFO, PSY-YSY, and most recently ASJ onwards (also "reversed" ASV). Even older vehicles have used remaining high 4 digit numbers in DS, BS and SV.

Q prefix. Where a vehicle needs to be reregistered, but either no proof of age exists, or the vehicle is made up of components of varying ages, a Q prefix mark will be issued. The format is Q, 2 or 3 digits, then three letters, which indicate the VRO of issue as for normal registrations, but Qs are in a separate series. Not to be confused with temporary imports in the format 123 QR, with 3 serial digits (or sometimes 4 in earlier years), "Q" and the year of registration, R prefix.

Trade number plates. Used by garages and manufacturers : they must be carried by vehicles driven on the road which are not currently taxed (including those not yet registered), and are moved from vehicle to vehicle as required. Unlike most other number plates, these have red characters on a white background and consist of 3 digits followed by 2 letters, or sometimes 4 digits and one letter. The allocation of the 2 letter codes originated with the old local authorities, and these have been inherited and continued by the VROs.