UK Data AtlasAPI

Translate an area code

Turn a code in one geography into its match in another: a ward into its local authority, or an old constituency into its 2024 successor.

get
/translations

Good to know

  • Use purpose to say what you need: identity for old codes to new, membership for what sits inside what, and apportion for areas that overlap.

Query parameters

  • fromstringrequired

    The code's exact source release, as {geography}/{release}.

  • codestringrequired

    The area code to translate, as published in from.

  • tostringrequired

    The exact target release, as {geography}/{release}.

  • purposestringoptional

    What the translation is for: official historical identity, clean membership, or area-overlap apportion. A crosswalk is used only where its method suits the purpose.

    One ofidentitymembershipapportion
    Defaultmembership

Returns

object

Matching published crosswalk records.

When it goes wrong

  • 400A query parameter is malformed or its cursor is not valid for this result set.
  • 422No published conversion supports the requested purpose.

Every error has the same shape. See Errors for how to handle them.

Technical notes

Show the precise behaviour

identity permits publisher-supplied historical lookups only, membership permits clean containment only, and apportion permits area-overlap crosswalks only. The resolver selects every published path with that purpose, ranking direct paths before reviewed and then discovered compositions. paths records every step used. A direct result retains its directional crosswalk and provenance; a composed result carries its full path instead, so it cannot be mistaken for a direct lookup. A composed result's targets carry only their code, labels and, for apportion, the weight multiplied along the path: a step's shares, overlap area and population describe the areas that step joins, not the queried one. Reverse area-overlap weights are normalised against the queried target and report its source coverage. A composed apportion result retains that first-step sourceCoverage and reports resolvedCoverage, the share of the queried source its final targets represent. The route does not treat a shared code across releases as proof of unchanged geography.