Register of Geographic Codes: Definitive UK Statistical Geographies for the 2021 Census

The UK's Register of Geographic Codes is the definitive list of statistical geographies maintained by the Office for National Statistics. This August 2022 version includes the new 2021 Census geographies and is a 20 MB file. It is published by the Government Digital Service and was last updated on the platform in August 2025.

Use Cases

• Link administrative datasets to official geographic areas based on the definitive code list.
• Analyze demographic changes across UK statistical geographies using the included 2021 Census boundaries.
• Maintain historical consistency in analyses by referencing the relationship between active and archived code ranges.

Strengths

• Definitive and authoritative source for UK statistical geographies, maintained by the Office for National Statistics.
• Includes the updated 2021 Census geographies, providing current boundary definitions.
• File size is specified as 20 MB, indicating a substantial but manageable download.

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.
• The core data is from August 2022, though the platform record was updated in 2025; freshness should be verified.

Provenance

Source

Office for National Statistics (ONS) on behalf of the Government Statistical Service.

Collection Method

Official maintenance and coordination of statistical geography codes.

Time Range

Snapshot from August 2022.

Freshness

Last updated 2025-08-11 08:00:29

Geography

United Kingdom