UK Postcode to Census Geography Best-Fit Lookup

Government Digital Service provides a best-fit lookup table linking UK postcodes to frozen 2011 Census geographies and current local authority districts. The dataset maps postcodes to Output Areas (OA), Workplace Zones (WZ), Lower Layer Super Output Areas (LSOA), Middle Layer Super Output Areas (MSOA), and Local Authority Districts (LAD), including their 2011 classifications. It is created by plotting the mean address location of each postcode into the target geographies.

Use Cases

• Aggregating address-based data to census Output Areas based on the OA11CD/OA21CD fields.
• Analyzing socioeconomic patterns using the Output Area Classification (OAC11CD/OAC11NM) linked to postcodes.
• Mapping service locations to Local Authority Districts (LADCD/LADNM) for local government reporting.
• Studying workplace demographics by linking postcodes to Workplace Zones (WZ11CD) and their classifications (WZC11CD/WZC11NM).

Strengths

• Provides a direct, official linkage between the fundamental UK addressing system (postcodes) and key statistical geographies.
• Includes classifications (OAC, WZC) from the 2011 Census, adding socioeconomic and functional context to the geographic units.
• Available on multiple government data platforms, indicating its importance and reliability for official use.

Limitations

• Sources conflict on the census year referenced: one describes a lookup to 'frozen 2011 Census' geographies, while another mentions '2021 Census Output Areas (OA)'.
• Key metadata such as row count, exact file size, and license information is missing from all provided sources.
• The 'best-fit' methodology, while practical, means some postcodes may be assigned to geographies based on a central point rather than precise polygon containment.

Provenance

Source

Government Digital Service

Collection Method

Best-fit assignment by plotting the location of a postcode's mean address into the boundaries of output geographies.

Time Range

Geographies are frozen from the 2011 Census; lookups are current as of May 2021 or May 2023, depending on the source version.

Freshness

Last updated on 2026-06-03 according to two sources, though this future date may be a placeholder or error.

Geography

United Kingdom