Mapping of all UK postcode districts

FOI reference: FOI-2023-1689

You asked

Please could you direct me to where I can find the most up to date mapping of all UK postcode districts and how they map to counties?

We said

Thank you for your Freedom of Information request. 

Here is a link to the Open Geography portal. From here you can source our data, including boundaries, maps, names and codes, lookups and the ONS Postcode Directory (ONSPD).

The ONSPD provides up-to-date full postcode information, and contains the files broken down by postcode area. You can map to the geography variables and if you use the multi csv option it will open in Excel. You can map from postcode to a range of variables e.g., Local Authorities, LSOAs, IMD etc. 

We strongly recommend reading the User Guide before use to familiarise yourself with the layout and variables etc. Please see Table 2 to identify the postcode areas you want. 

The ONSPD is a very large file so it may be an idea to either use software which is capable of opening and reading large files, or alternatively use the multi-csv files from the ONSPD instead, once you have established the postcodes you require as this is their intention. Here is a link to the latest ONSPD.

When counties (and their constituent county electoral divisions) are replaced by Unitary Authorities, they are removed from the county and county electoral division names and codes files as those geographical entities are no longer in force.

The reason these names do not appear in the 'county' names and codes file and have a code of 'E99999999' is because they are not administrative counties. Also, the top tier of admin area in Wales is unitary authority and in Scotland is council area (see OSLAUA field and LA_UA names and codes file). Please see the following example details: 

Berkshire is a ceremonial county and is covered by the unitary authorities of Bracknell Forest, Reading, Slough, West Berkshire, Windsor and Maidenhead and Wokingham (see OSLAUA field). 

Buckinghamshire is no longer a county (as of April 2020) - it is a unitary authority and is covered by the non-metropolitan districts of Aylesbury Vale, Chiltern, South Bucks and Wycombe (see OSLAUA field). 

West Midlands is a metropolitan county rather than a county and is covered by the metropolitan districts of Birmingham, Coventry, Dudley, Sandwell, Solihull, Walsall and Wolverhampton (see OSLAUA field). 

Here is a link to the ONSPD User Guide which accompanies the data. The extract in the associated downloads should also help. 

If you need anything further, please do not hesitate to contact us.