What is the definition of a postcode area?
The UK is split into 124 postcode areas. These areas are used by the Royal Mail to help sort out post, so they can define which geographical location the mail should be delivered to. An area can consist of one or two letters. Glasgow's postcode area is just 'G' whilst many other areas such as Harrogate are two 'HG'. The letters also correspond to the name of the local area, for example, 'WF' takes the first letters of each syllable in Wakefield and York's area is the first two letters of the word 'YO'.
When combined with the postcode district, this selection of digits defines a specific geographical area that the letter can be sent to, and sorted into smaller geographies so it can eventually be delivered to the right person.
How are postcode areas selected?
UK areas are not split in the same way as political constituencies. They also aren't split into geographies of equal land mass size, one of the biggest examples of this is 'BT' compared to 'EC'. The 'BT' (Belfast) postcode area covers all of Northern Ireland and over 14,000 squarekilometres whereas 'EC' covers East Central London areas and includes, in part, some of London's most densely populated Boroughs including parts of Islington, Camden and Tower Hamlets.
London areas not to scale to Belfast as zoomed in for detail. Map screenshots are taken from Map Marketing.
Postcode list providers
Here are a few sources where you can download a list of all areas:
Postcode areas map providers
Image above Contains Ordnance Survey and Royal Mail data © Crown copyright and database right.
Here are a few sources where you can download or purchase a map or check out our postcode mapping guide here.
The break down of a UK postcode
All UK postcodes are made up of a range of different letters and numbers and follow this format: A postcode area, district, sector, unit.
Learn more about postcodes at our postcode map and list resource centre.