Postcodes in The United Kingdom - Development

Development

The Post Office experimented with electromechanical sorting machines in the late 1950s. These devices would present an envelope to an operator, who would press a button indicating which bin to sort the letter into. Postcodes were suggested to increase the efficiency of this process, by removing the need for the sorter to remember the correct sorting for as many places. In January 1959 the Post Office analysed the results of a survey on public attitudes towards the use of postal codes. The next step would be to choose a town in which to experiment with coded addresses. The envisaged format was a six character alphanumeric code with three letters designating the geographical area and three numbers to identify the individual address. On 28 July Ernest Marples, the Postmaster General, announced that Norwich had been selected, and that each of the 150,000 private and business addresses would receive a code by October. Norwich had been selected as it already had eight automatic mail sorting machines in use. The original Norwich format consisted of the three letters "NOR" followed by a space, then a two digit number (which, unlike the current format, included a leading zero for numbers less than 10) and a single final letter (instead of the two final letters in the current format).

In October 1965 it was confirmed that postal coding was to be extended to the rest of the country in the "next few years". On 1 May 1967 postcodes were introduced in Croydon. The codes for central Croydon started with the three letters CRO, and those of the surrounding post towns with CR2, CR3 and CR4. This was to be the beginning of a ten year plan, costing an estimated £24 million. Within two years it was expected that coding would be used in Aberdeen, Belfast, Brighton, Bristol, Bromley, Cardiff, Coventry, Manchester, Newcastle upon Tyne, Newport, Reading, Sheffield, Southampton and the Western district of London. By 1967 codes had been introduced to Aberdeen, Southampton, Brighton and Derby. In 1970 codes were introduced to the Western and North Western London areas. In December 1970 Christmas mail was franked with the message "Remember to use the Postcode", although codes were only used to sort mail in a handful of sorting offices.

During 1971 occupants of addresses began to receive notification of their postcode. Asked in the House of Commons about the completion of the coding exercise, the Minister of State for Posts and Telecommunications (whose role superseded that of Postmaster General in 1969), Sir John Eden, stated that it was expected to be completed during 1972. The scheme was finalised in 1974 when Norwich was completely re-coded but the scheme tested in Croydon was sufficiently close to the final design for it to be retained, with CRO standardised as CR0 (district zero). The central Newport area was originally allocated NPT, in a similar way to Norwich and Croydon, with the surrounding areas allocated NP1–NP8. This lasted until the end of 1984 when for operational reasons (NPT being non-standard and too similar to NP7) it was recoded to NP9. Girobank's GIR 0AA, the last domestic postcode with a wholly alphabetical outward code, no longer exists in the Royal Mail's PAF system, but remains in active use by the bank's owners, currently Santander UK.