ONS Postcode Directory: UK Postcode to Geographic Area Linkages (May 2026)

United Kingdom postcodes linked to administrative, electoral, health, and census geographies as of May 2026. The Office for National Statistics (ONS) Geography produces this directory, which includes both current and terminated postcodes. It supports the production of area-based statistics from postcoded data and is issued quarterly.

Use Cases

• Aggregate customer or survey data to administrative regions based on postcode linkages.
• Analyze demographic patterns by linking postcodes to 2021 and 2001 Census Output Areas.
• Map health statistics to current and pre-2002 health area geographies.
• Support electoral analysis by relating postcodes to electoral wards and constituencies.

Strengths

• Links postcodes to a wide range of current and historical statutory geographies, including health areas and census zones.
• Includes both current and terminated UK postcodes, providing historical continuity.
• File size is 235 MB, suggesting a substantial dataset.
• Updated quarterly, indicating a regular maintenance schedule.

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 processing.
• Description metadata is limited; actual data quality requires manual inspection after download.

Provenance

Source

Office for National Statistics (ONS) Geography

Collection Method

Produced by ONS Geography to provide geographic support and services.

Time Range

Snapshot as of May 2026; includes historical linkages.

Freshness

Issued quarterly; snapshot dated May 2026.

Geography

United Kingdom (England, Wales, Scotland, Northern Ireland)