A postal code is a series of letters or digits or both, sometimes including spaces or punctuation, included in a postal address for the purpose of sorting mail.
Postal codes used in the United Kingdom, British Overseas Territories and Crown dependencies are known as postcodes. They are alphanumeric and were adopted nationally between 11 October 1959 and 1974, having been devised by the General Post Office. A full postcode is known as a "postcode unit" and designates an area with several addresses or a single major delivery point.
The London postal district is the area in England of 241 square miles (620 km2) to which mail addressed to the London post town is delivered. The General Post Office under the control of the Postmaster General directed Sir Rowland Hill to devise the area in 1856 and throughout its history it has been subject to reorganisation and division into increasingly smaller postal units, with the early loss of two compass points and a minor retraction in 1866. It was integrated by the Post Office into the national postcode system of the United Kingdom during the early 1970s and corresponds to the E, EC, N, NW, SE, SW, W and WC postcode areas. The postal district has also been known as the London postal area. The County of London was much smaller, at 117 square miles (300 km2), but Greater London is much larger at 607 square miles (1,570 km2).
The W postcode area, also known as the London W postcode area is a group of postcode districts covering part of central and part of West London, England. The area originates from the Western (W1) and Paddington (W2-14) districts of the London postal district. This area covers 35 postcode districts and around 18,554 live postcodes.
The E (Eastern) postcode area, also known as the London E postcode area, is the part of the London post town covering much of east London, England. It borders the N postcode area to the west, both north of the tidal Thames. Since closure of the East London mail centre its mail is sorted at Romford Mail Centre together with IG and RM postcode areas.
The IG postcode area, also known as the Ilford postcode area, is a group of eleven postcode districts in England, within six post towns. These cover parts of eastern Greater London and south-west Essex. Inward mail for the area is sorted, along with mail for the E and RM postcode areas, at the Romford Mail Centre.
The SM postcode area, also known as the Sutton postcode area, is a group of seven postcode districts in England, within five post towns. These cover part of south-west London, as well as a small part of north Surrey.
A "postal address" in Ireland is a place of delivery defined by Irish Standard (IS) EN 14142-1:2011 and serviced by the universal service provider, An Post. Its addressing guides comply with the guidelines of the Universal Postal Union (UPU), the United Nations-affiliated body responsible for promoting standards in the postal industry, across the world.
The KA postcode area, also known as the Kilmarnock postcode area, is a group of 30 postcode districts in south-west Scotland, within 23 post towns. These cover East Ayrshire, North Ayrshire and South Ayrshire.
The DN postcode area, also known as the Doncaster postcode area, is a group of 32 postcode districts in England, which are subdivisions of 13 post towns. These cover eastern South Yorkshire, north Lincolnshire, small parts of Nottinghamshire and the East Riding of Yorkshire, and a very small part of North Yorkshire.
The S postcode area, also known as the Sheffield postcode area, is a group of postcode districts in England, which are subdivisions of eight post towns. These cover most of South Yorkshire, parts of north Derbyshire and north-west Nottinghamshire, plus a small part of West Yorkshire.
The NW postcode area, also known as the London NW postcode area, is a group of 13 postcode districts covering around 13,895 live postcodes within part of northwest London, England. It is the successor of the NW sector, originally created as part of the London postal district in 1856.
The SE postcode area covers a broad radial swathe of the south-east of the London post town from the Albert Embankment to West Heath and the nearest edges of Sidcup and Selhurst. It loosely corresponds to the boroughs of Southwark, Lewisham and Greenwich plus indicated parts of the boroughs of Croydon (north), Lambeth (east), Bexley (west) and Bromley.
The NE postcode area, also known as the Newcastle upon Tyne postcode area, is a group of 61 postcode districts in north-east England covering 34 post towns. These cover most of Tyne and Wear and Northumberland, plus a very small part of northern County Durham.
The PL postcode area, also known as the Plymouth postcode area, is a group of 35 postcode districts in South West England, within 25 post towns. These cover west Devon and east Cornwall.
The N (Northern) postcode area, also known as the London N postcode area, is the part of the London post town covering part of North London, England. It is a group of 25 postcode districts which covers around 17,429 live postcodes.
The G postcode area, also known as the Glasgow postcode area, is a group of postcode districts in central Scotland, within five post towns. These districts are primarily centered on Glasgow itself, and West Dunbartonshire, plus parts of the council areas of Argyll and Bute, East Dunbartonshire, North Lanarkshire, South Lanarkshire, East Renfrewshire and Stirling.
The SW postcode area, also known as the London SW postcode area, is a group of 20 postcode districts within the London post town in England. The area comprises the South Western operational district and the Battersea operational district, and is the only area within the London post town to lie on both sides of the River Thames.
