By the 1850s, the rapid growth of the metropolitan area meant it became too large to efficiently operate as a single post town. A Post Office inquiry into the problem had been set up in 1837 and a House of Commons committee was initiated in 1843. In 1854 Charles Canning, the Postmaster General, set up a committee at the Post Office in St. Martin's Le Grand to investigate how London could best be divided for the purposes of directing mail. In 1856, of the 470,000,000 items of mail sent in the United Kingdom during the year, approximately one fifth (100,000,000 items) were for delivery in London and half of these (50,000,000 items) also originated there.
The original London postal district was devised by Sir Rowland Hill in 1856 as a circular area of 12 miles radius from the central post office at St. Martin's Le Grand, near St Paul's Cathedral in central London. As originally devised, it extended from Waltham Cross in the north, to Carshalton in the south and from Romford in the east to Southall in the west. Within the district it was divided into ten large areas which operated much like separate towns. Each was constituted "London" with a suffix (EC, WC, N, NE, E, SE, S, SW, W, and NW) indicating the area it covered; each had a separate head office. The system was introduced during 1857 and was completed on 1 January 1858.
The NE and S divisions were abolished following a report by Anthony Trollope. In 1866 NE was merged into the E district, transferring places such as Walthamstow, Wanstead and Leytonstone. Also at this time the outer boundary was retracted in the east, removing places such as Great Ilford from the postal district altogether. In 1868 the S district was split between SE and SW. The NE and S codes have been re-used in the national postcode system and now refer to the NE postcode area around Newcastle Upon Tyne and the S postcode area around Sheffield.
In 1965 the creation of Greater London caused London's boundary to expand to include these places for local government as well as postal purposes. However the new boundary went far beyond these postal districts. Royal Mail were unable to follow this change and expand the postal district to match because of the prohibitive cost. Places in London's outer boroughs such as Harrow, Enfield, Ilford, Romford, Bromley, Richmond and Croydon are therefore covered by parts of twelve adjoining postcode areas (EN, IG, RM, DA, BR, TN, CR, SM, KT, TW, HA and UB) in five former postal counties. Royal Mail now has a policy of changing postcodes only if there is an operational advantage to them and has no plan to change the postcode system to match up with the Greater London boundaries. In 2003 the then Mayor of London expressed support for revision of postal addresses in Greater London.
The London postal district currently includes:
|Entirely included||City of London, Camden, Hackney, Hammersmith and Fulham, Haringey, Islington, Kensington and Chelsea, Lambeth, Southwark, Tower Hamlets, Wandsworth, Westminster|
|Mostly included||Greenwich, Lewisham, Newham, Waltham Forest|
|Partly included||Barnet, Bexley, Brent, Bromley, Croydon, Ealing, Enfield, Harrow, Hounslow, Kingston upon Thames, Merton, Redbridge, Richmond upon Thames|
|Not included||Barking and Dagenham, Havering, Hillingdon, Sutton|
All London postal districts were traditionally prefixed with the post town 'LONDON' and full stops were commonly placed after each character, e.g. LONDON S.W.1.
Use of the full stops ended with the implementation of the national postcode system. More recently, the Royal Mail have specified that the post town and district should each appear on a separate line in order to increase the effectiveness of their OCR equipment.
|Postcode area||District||Postcode districts with locality served or name of delivery office|
|E||Eastern||E1 Head district • E2 Bethnal Green • E3 Bow • E4 Chingford • E5 Clapton • E6 East Ham • E7 Forest Gate • E8 Hackney • E9 Homerton • E10 Leyton • E11 Leytonstone • E12 Manor Park • E13 Plaistow • E14 Poplar • E15 Stratford • E16 Victoria Dock • E17 Walthamstow • E18 South Woodford|
|EC||Eastern Central||EC1 Head district • EC2 Bishopsgate • EC3 Fenchurch Street • EC4 Fleet Street|
|N||Northern|| N1 Head district • N2 East Finchley • N3 Finchley • N4 Finsbury Park • N5 Highbury • N6 Highgate • N7 Holloway • N8 Hornsey • N9 Lower Edmonton • N10 Muswell Hill • N11 New Southgate • N12 North Finchley • N13 Palmers Green • N14 Southgate • N15 South Tottenham|
N16 Stoke Newington • N17 Tottenham • N18 Upper Edmonton • N19 Upper Holloway • N20 Whetstone • N21 Winchmore Hill • N22 Wood Green
|NW||North Western||NW1 Head district • NW2 Cricklewood • NW3 Hampstead • NW4 Hendon • NW5 Kentish Town • NW6 Kilburn • NW7 Mill Hill • NW8 St John's Wood • NW9 The Hyde • NW10 Willesden • NW11 Golders Green|
|SE||South Eastern||SE1 Head district • SE2 Abbey Wood • SE3 Blackheath • SE4 Brockley • SE5 Camberwell • SE6 Catford • SE7 Charlton • SE8 Deptford • SE9 Eltham • SE10 Greenwich • SE11 Kennington • SE12 Lee • SE13 Lewisham • SE14 New Cross • SE15 Peckham • SE16 Rotherhithe • SE17 Walworth • SE18 Woolwich • SE19 Crystal Palace • SE20 Anerley • SE21 Tulse Hill • SE22 Dulwich • SE23 Forest Hill • SE24 Herne Hill • SE25 South Norwood • SE26 Sydenham • SE27 West Norwood • SE28 Thamesmead|
|SW||South Western||SW1 Head district • SW2 Brixton • SW3 Chelsea • SW4 Clapham • SW5 Earls Court • SW6 Fulham • SW7 South Kensington • SW8 Vauxhall • SW9 Stockwell • SW10 West Brompton|
|Battersea||SW11 Head district • SW12 Balham • SW13 Barnes • SW14 Mortlake • SW15 Putney SW16 Streatham • SW17 Tooting • SW18 Wandsworth • SW19 Wimbledon • SW20 West Wimbledon|
|W||Western||W1 Head district|
|Paddington||W2 Head district • W3 Acton • W4 Chiswick • W5 Ealing • W6 Hammersmith • W7 Hanwell • W8 Kensington • W9 Maida Vale • W10 North Kensington • W11 Notting Hill • W12 Shepherds Bush • W13 West Ealing • W14 West Kensington|
|WC||Western Central||WC1 Head district • WC2 Strand|
The post towns of neighbouring postcode areas cover the rest of Greater London:
|Postcode area||Post town||Postcode districts|
|EN||ENFIELD||EN1, EN2, EN4|
|HARROW||HA1, HA2, HA3|
|IG||ILFORD||IG1, IG2, IG3, IG4, IG5, IG6|
|KT||KINGSTON UPON THAMES||KT1, KT2|
|RM||ROMFORD||RM1, RM2, RM3, RM4, RM5, RM6, RM7|
|DAGENHAM||RM8, RM9, RM10|
|SM||SUTTON||SM1, SM2, SM3|
|HOUNSLOW||TW3, TW4, TW5, TW6|
|UXBRIDGE||UB8, UB9, UB10|