Postcodes
London was divided into postal districts in 1857, on Rowland Hill’s watch, and the districts were compass-based: EC, WC, N, NE, E, SE, S, SW, W, NW. In 1917, with the war absorbing experienced sorters and their replacements lacking the local knowledge that had previously done the work, the districts were subdivided and numbered — and the numbering scheme is one of my favourite pieces of accidental poetry in the whole of British infrastructure. Within each compass district, the number 1 went to the head district office. The remaining sub-districts were then numbered in alphabetical order of their names.
This is why London postcodes make no geographic sense. NW1 is Camden Town because that is where the head office was; after that, NW2 is Cricklewood, NW3 Hampstead, NW4 Hendon, NW5 Kentish Town, NW6 Kilburn, and so on down the alphabet, scattering the numbers across the map like dropped cutlery. Generations of Londoners have assumed the numbers radiate outward and been baffled by the results. They radiate through the alphabet. It is a filing system that was mistaken for a map, and it has been quietly misleading people for over a century.
The full modern British postcode, developed through the 1960s — the first trials ran in Norwich in 1959, and national coverage was completed in 1974 — went considerably further than anyone else. Most countries’ postcodes identify a town or a district. The British one narrows to an average of about fifteen addresses. That granularity is why so much British administrative life runs on the postcode: insurance quotes, school catchments, deprivation indices, political analysis, and the satnav destination that gets a driver to within a few doors.
