Proposal:HM Land Registry

HM Land Registry
Proposal status:	Draft (under way)
Proposed by:	Mattbaker-digital
Draft started:	2026-06-28

Problem Statement

OpenStreetMap currently has no standardised method for tagging UK land parcels or address features with their corresponding HM Land Registry Title Number.

This creates several problems:

• INSPIRE Index Polygons, published as open data, represent the indicative extent of registered titles, but they do not include the Title Number within the dataset.
• The Title Number is publicly accessible, but only through manual lookup on the HM Land Registry website, meaning contributors cannot record it in OSM using any existing tagging scheme.
• As a result, data consumers cannot reliably link OSM land parcels or address features to authoritative property datasets, limiting interoperability with planning systems, conveyancing tools, and property intelligence platforms.
• Existing OSM tags (e.g., ref=*, ref:GB:*, ref:cadastre=*) do not provide a clear, unambiguous place to store UK Title Numbers without causing confusion with other reference systems.

The absence of a dedicated tagging scheme makes it difficult for mappers to record a widely used, stable, and publicly accessible identifier for UK land parcels.

https://www.gov.uk/search-property-information-land-registry

https://www.gov.uk/guidance/inspire-index-polygons-spatial-data

Proposal

Introduce a new, UK‑specific reference tag:

ref:GB:title_number=*

This tag stores the HM Land Registry Title Number associated with a land parcel, building, or address feature.

ref:GB:inspire_id=*

This tag stores the INSPIRE Index Polygon ID associated with a land parcel, building, or address feature.

Applicable database elements

• Areas / Ways
  • INSPIRE Index Polygons imported or manually drawn
  • Land parcels mapped by contributors
• Relations
  • Multipolygons representing complex parcels
• Nodes
  • Address nodes where the title number is known and relevant

No existing tags are deprecated. This proposal introduces a new, unambiguous key.

Rationale

Why this solves the problem

• Provides a clear, dedicated place to store Title Numbers without overloading generic tags like ref=*.
• Aligns with existing OSM practice of country‑specific reference namespaces (e.g., ref:FR:cadastre, ref:AT:grundbuch).
• Avoids ambiguity with other UK reference systems (UPRN, USRN, TOID).
• Enables data consumers to reliably join OSM features with HM Land Registry datasets, planning systems, and property metadata platforms.

Why this key name

• ref: — consistent with OSM’s convention for external identifiers.
• GB: — matches ISO 3166‑1 alpha‑2 and existing UK‑specific tags.
• title_number / inspire_id — clear, descriptive, and avoids confusion with other registries or cadastral systems.
• British English spelling is used, per OSM UK conventions.

Significance and potential uses

• Linking OSM polygons to Title Numbers enables:
  • property boundary visualisation
  • planning application cross‑referencing
  • conveyancing tools
  • property metadata platforms
  • research into land ownership patterns
• Title Numbers are stable identifiers and widely used across UK property systems.

Examples

Example 1 — INSPIRE Polygon (way)

<landuse=residential
ref:GB:inspire_id=21600874

Example 2 — Multipolygon relation

<type=multipolygon
landuse=commercial
ref:GB:title_number=BK987654

Example 3 — Address node

<addr:housenumber=12
addr:street=High Street
ref:GB:title_number=GL445566

Comments

Please comment on the discussion page.