History of UK Vehicle Registrations

Origins & Allocation of Marks

On 1st January, 1904, the UK government introduced a law (The Motor Car Act 1903) which stipulated that all motorised vehicles should be identified by distinguishing marks, now known as registration numbers, so that they may be easily traced in the event of accidents or contravention of laws The original law specified that each identifying mark would have a maximum of six characters and would have either a single letter or two letters to indicate the local authority that registered the vehicle, followed by up to five numbers, e.g. [AB 1234].

The allocation of index marks to English & Welsh County Councils & County Borough Councils was single letters from A to Y, and double letters AA to FP (with some gaps e.g. for Scotland and Ireland – see below). These were arranged in order of population figures from the 1901 census from London with letter A to Rutland with FP.

At an early stage it was decided that I and Z were to be allocated to Ireland and G, S and V were to be allocated to Scotland’s authorities – though many G and V combinations were diverted elsewhere as it became clear that Scotland would not require all of these marks. Unlike England & Wales, the allocations to Ireland & Scotland were made in alphabetical order of counties, followed by boroughs, with a few exceptions.

Blackpool and Tynemouth, awarded CBC status later in 1904, took the next available marks FR and FT. Then, as each authority reached the end of its allotted mark, it was allocated another. London was quickly awarded LC, LN, LB, etc. In this way, the areas with larger populations received more marks as required, whilst the smallest areas only received one mark.

In 1932 the first three letter combination, ARF, appeared for Staffordshire. The first letter was a serial, which preceded the existing two letter mark. Many councils issued marks in the order of their original issue; Bedfordshire for example issued ABM, ANM, ATM, AMJ, then BBM etc.


Scotland was ostensibly allocated all index marks containing the letters G, S or V, and the single-letter codes were allocated to Glasgow, Edinburgh and Lanarkshire respectively. Each county was allocated one mark each in alphabetical order with codes beginning with S, so SA for Aberdeenshire, SB for Argyllshire, SD for Ayrshire, SE for Banffshire and so on. There were some “out of sequence” oddities, e.g. SC, SF and SG were allocated to Edinburgh rather than the next county in the sequence.

Once these had been allocated as far as SY (Midlothian – SZ was allocated to County Down in Northern Ireland – see below), the sequence continued with the ‘S’ as the second element starting with AS (Nairnshire), BS (Orkney) through to PS (Zetland, or Shetland). The remaining ‘S’ codes were allocated to burgh councils with Aberdeen receiving RS, Dundee TS, Glasgow US and so on. Any remaining requirements were to be met out of the ‘G’ and ‘V’ sequence, so for example GA, GB, GD, GE and GG went to Glasgow, GM to Motherwell and Wishaw, AG to Ayrshire, FG to Fife, RG to Aberdeen and WG to Stirlingshire, whilst VA and VD went to Lanarkshire and AV to Aberdeenshire. This system, however, resulted in too many for Scottish requirements and were therefore not all used by Scottish authorities. The remaining codes in these sequences were therefore allocated to authorities in England and Wales. The only mark outside of the ‘G’, ‘S’ and ‘V’ marks issued to a Scottish authority was YJ, which was allocated to Dundee in 1932.


In Ireland the ‘I’ series was initally allocated to the counties in alphabetical order, beginning with IA for Antrim, IB for Armagh, IC to Carlow, ID to Cavan and so on (at that time all of Ireland was still part of the UK). As with the Scottish system, cities were allocated marks later in the sequence, from OI (Belfast) to YI (Dublin).

In the late 1920s marks with the letter ‘Z’ were introduced. As this was following partition in 1922, the marks were split, with those beginning with ‘Z’, i.e. ZA, ZB, ZC etc going to the Republic and those ending with ‘Z’, i.e. AZ, BZ, CZ etc going to Northern Ireland.

In contrast to the rest of the UK, after Northern Ireland had issued two letter marks in the order they were allocated, followed by “reversed” two letter marks, the three letter combinations were issued with up to 4-digit numbers resulting in a 7-symbol system, e.g. [ABZ 1234]. This is the system still being used there at the time of writing.

The Republic of Ireland continued working with the British system after 1922 issuing new marks as required. The issue of marks was via the two letter, three letter, “reversed” two letter, and “reversed” three letter systems as in the UK, but as in Northern Ireland the year-letter suffix/prefix system was never used. In 1986 a completely new, numeric year-based system with one single or double letter symbol per county or city was introduced. Under this system the first two numbers represented the year, followed by one or two letters and a further four or five numbers issued sequentially, e.g. [90-D-12345] represented a vehicle registered in Dublin in 1990. See the “Ireland” page for more details.

Three-letter marks

In Great Britain, by the 1930s, despite the larger authorities being allocated a larger number of index marks, the available codes were running out, so the system was extended to replace one number in the two-letter system with a letter. This extra letter was added before the index mark, however, so for example Reading, which had two index marks, DP and RD, issued [ADP 1] to [ADP 999] in 1937-1938, then [ARD 1] to [ARD 999] in 1938. Then in 1939 the sequence continued with [BDP 1] to [BDP 999], followed by [BRD 1] to [BRD 999] and so on. All authorities that exhausted their two-letter combinations moved onto this new system as and when required.

Reversed Registrations

By the 1950s, many authorities had already exhausted the [ABC 123] combinations and needed another new system to distinguish newly registered vehicles from old ones. The solution adopted was to reverse the sequence from letters followed by numbers to placing the numbers before the letters. Different authorities used reversed versions of the single-letter, two-letter and three-letter systems depending on their needs at the time.

Annual Suffix Letter

As these marks were also fast running out by the early 1960s, another new system was needed to extend the issue of registrations into the future. Thus a “suffix” letter denoting the year of registration was added to numbers in the format [ABC 123A]. The suffix letter system was phased in from 1963-5, with ‘A’ representing vehicles registered in 1963. Because authorities had used up their allocations at vastly different rates, e.g. Somerset County Council had reached the “reversed” YYC mark, whereas small authorities such as Buteshire in Scotland had only reached [SJ 2860], and therefore had only used a fraction of the available combinations by 1964, only the larger authorities generally started at ‘A’. Most remaining authorities didn’t issue suffixed registrations until 1964 with the ‘B’ suffix. There were still some of the very smallest authorities, however, that had not come onto the new system so it was mandated that all authorities use the new system, beginning with the ‘C’ suffix in 1965.

In the first four years the suffix letters were issued from January to December, with ‘A’, ‘B’, ‘C’ and ‘D’ representing 1963, 1964, 1965 and 1966 respectively. However, this produced too much demand at the start of the year and, following pressure from the motor industry, the new suffix for each year was introduced in August instead of January. Hence, ‘E’ was issued from January 1967 as normal, but ‘F’ was then brought in from August the same year. This system was used until 1983, with only the letters ‘I’, ‘O’, ‘Q’, ‘U’ and ‘Z’ being excluded to prevent ambiguity. In August 1983, after the ‘Y’ suffix year, the system was again reversed, with the year letter as a prefix rather than a suffix, e.g. [A123 ABC].

In 1999, a six-monthly period was introduced, with two letters being used each year beginning in March and September to try to even out demand over the year. The ‘T’ prefix was issued from March 1999, ‘V’ in September 1999, ‘W’ in March 2000, ‘X’ in September 2000 and, finally, ‘Y’ in March 2001. From September 2001 an entirely new system was introduced.

New Registration System

From September 2001 an entirely new system was introduced in the format [AB12 CDE]. The first two letters were a location indicator, with the first letter denoting a region and the second letter allocated to an issuing office within each region. For example, Scotland has the ‘S’ prefix, and the allocation of marks to offices within Scotland are, sequentially, SA to SJ to Glasgow, SK to SO to Edinburgh, SP to ST to Dundee, SU to SW to Aberdeen and SX and SY to Inverness.

The next two numbers indicate the six-month period in which the vehicle was registered. For the March issue each year, the last two digits of the year are used, so ’02’ for March to August 2002, ’03’ for March to August 2003 and so on. The September issue use the last two digits of the year plus 50, so September 2001 to February 2002 is ’51’, September 2002 to March 2003 is ’52’ and so on. At the time of writing (December 2017), the year indicator is ’67’. (Note that the year code ’01’ was not used as the new system began in September 2001 with the ’51’ code.

The final three letters of the registration are issued randomly and, as the letter ‘Z’ can now be used in this portion of the registration number for the first time, this gives a possible total of 13,824 registrations for each combination of the location and year indicators, minus a few ‘unacceptable’ combinations such as ‘ARS’, ‘FUK’ etc. This system will last for almost 50 years until the issue of the ’99’ indicator in September 2049.

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