Postcode products

We produce two key postcode products – the ONS Postcode Directory (ONSPD) and the National Statistics Postcode Lookup (NSPL) – which are used by a wide variety of customers, including central and local government, private industry and academia.

National Statistics Postcode Lookup (NSPL)

If you are a producer of National Statistics, you should use the NSPL to allocate your 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 authority districts) by a best-fit methodology that uses Census population data.

The methodology used within the NSPL to allocate postcodes to higher geographies is different from that used in the ONSPD. For further information, see “A Guide to ONS Geography Postcode Products”

This product supports the Geography Policy for National Statistics (see downloads).

ONS Postcode Directory (ONSPD)

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 a wide range of administrative, health and other geographic areas in which each postcode falls using a point-in-polygon methodology.

You should note that postcodes with addresses that straddle a boundary will be assigned to the area where the mean grid reference of all the addresses within that postcode falls.

Which postcode product should I use?

A Guide to ONS Geography Postcode Products

Product details and availability

The ONSPD and NSPL are available with grid references at 1-metre resolution, covering the UK.

Information on the latest postcode changes is available on the Royal Mail website.

We release our postcode products quarterly in February, May, August and November each year and they are available to download, free of charge, from the Open Geography portal.

Here are the licensing details.

We provide our postcode products in the following formats:

TXT – fixed record length with no text qualifiers

CSV – variable record length with data items delimited by commas and qualified with double quotes, with field headings.

We include a user guide, providing comprehensive information about the products, with the data.