ONS Geography produces two key postcode products – National Statistics Postcode Lookup (NSPL) and the ONS Postcode Directory (ONSPD) - that are used by a variety of customers, including central and local government, private industry and academia.
National Statistics Postcode Lookup (NSPL)
The NSPL should be used by producers of National Statistics to allocate their source statistics at postcode level to a wide range of higher geographies.
The NSPL does this by allocating UK postcodes to output areas (OA) using the same methodology as that for the ONSPD. These OAs are then referenced to a wide range of higher geographies, for example local authorities, by a best-fit methodology that uses census population data.
Two NSPL versions are currently available - one based on 2001 Census output areas and one based on 2011 Census output areas. Both are included in the NSPL download.
The methodology used within the NSPL to allocate postcodes to higher geographies is different from that used in the ONSPD. For further information see ‘Which postcode product should I use?’ section further down the page.
This product supports the Geography Policy for National Statistics, see ‘Downloads’ section for more details
ONS Postcode Directory (ONSPD)
The ONSPD is a key ONS Geography product and is used by a variety of customers, including central and local government, private industry and academia
The ONSPD is a Gridlink® branded product that pulls together data from members of the Gridlink® Consortium (Royal Mail, Ordnance Survey, National Records of Scotland, Land & Property Services (Northern Ireland) and ONS).
It links all current and terminated UK postcodes to the administrative, health and other geographic areas in which each postcode falls.
Users should note that postcodes that straddle two geographic areas will be assigned to the area where the mean grid reference of all the addresses within the postcode falls.
Which postcode product should I use?
The ONSPD and NSPL are available with grid references at 1 metre resolution with UK coverage.
Information on the latest postcode changes is available on the Royal Mail website.
Postcode products are released quarterly in February, May, August and November and are available to download, free of charge, from the Open Geography portal.
For licensing details please see 'Related Links'
Postcode products are provided in all the following formats: TXT, CSV DBF, MDB and multi-csv.
TXT - fixed record length with no text qualifiers.
CSV - Variable record length with data items delimited by commas and qualified with double quotes.
DBF - Dbase IV format data, with column headings
MDB - MS Access 2000
Multi-csv - one file per postcode area (for ease of use in commercial spreadsheet packages)
Version Notes and a User Guide provides comprehensive information about the products and are included with the data.
Availability and cost
Products are available as a zipped download free of charge, or by special request on disk at a cost of £50 + VAT per CD / DVD in line with the ONS charging policy.