What this is, who runs it, where the data comes from, and what we log.
uprns.io is a free, open reference for UK Unique Property Reference Numbers. Type a UPRN, postcode or street (USRN) and get a clean, canonical page - coordinates, administrative geography and linked identifiers - with the same data available as JSON over a no-key API and as bulk Parquet downloads. It exists to make the open address graph genuinely easy to use, whether you are debugging one record or joining millions.
uprns.io is built by the team at Ideal Postcodes. We also provide postcodes.io, which serves 2bn API requests every month.
Everything here is assembled from official open datasets. We keep them current and join them into a single graph - we don’t alter the underlying records.
OS Open UPRN
Every UPRN in Great Britain with its coordinates in WGS84 and British National Grid.
OGL v3OS Open USRN
Unique Street Reference Numbers with geometry, and street names where published.
OGL v3OS Open Linked Identifiers
The crosswalk that joins UPRN ↔ USRN ↔ TOID, so records line up across datasets.
OGL v3ONS Postcode Directory
Postcode → administrative, electoral and census geography (ONSPD).
OGL v3In line with the Open Government Licence, products built on this data must carry: “Contains OS data © Crown copyright and database right 2026”, and acknowledge ONS and Royal Mail where postcode geography is used.
Found a wrong record, a missing UPRN, or have an idea? We read everything.