Postcode to Westminster Constituency Lookup for England and Wales (2024)

England and Wales postcodes from January 2024 are mapped to the new Westminster Parliamentary Constituencies effective from July 2024. The lookup is provided by the Government Digital Service and is best-fitted from 2021 Census Output Areas. The file is 18MB in size and was last updated on the platform in August 2025.

Use Cases

• Mapping postcode-level data to new parliamentary constituencies for electoral analysis.
• Aggregating demographic or economic statistics from Output Areas to constituency level.
• Validating or updating geographic information systems (GIS) with the July 2024 constituency boundaries.

Strengths

• Provides a direct mapping from a specific temporal snapshot (January 2024 postcodes).
• Links to a major political boundary change (July 2024 constituencies).
• File size of 18MB suggests a detailed, nationwide coverage.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment for large-scale joins.

Provenance

Source

Government Digital Service

Collection Method

Best-fit lookup from 2021 Census Output Areas.

Time Range

Postcodes as of January 2024, constituencies operable from July 2024.

Freshness

Last updated 2025-08-13 13:16:38; freshness should be verified.

Geography

England and Wales