UPRN
How do I find a UPRN for an address?
There are three reliable routes to a UPRN. The easiest is to enter a UK address into a UPRN lookup tool such as Homedata's free UPRN Lookup, which resolves a free-text address to the matched 12-digit reference and shows the joined property record.
The second route is the open OS Open UPRN CSV/GeoPackage download from Ordnance Survey. It contains every UPRN with its coordinates, but no address strings — you have to join it to OS Open Names or AddressBase to get a usable address.
For programmatic access, use an address-matching API. Submit an address string and the API returns the matched UPRN plus a confidence score, which is the right approach for bulk enrichment, CRM imports or onboarding flows. Free-text input typed by users rarely matches AddressBase exactly, so fuzzy matching is essential.
What this means in practice
Say a tenant types "Flat 2, 14 Acacia Road, Camden NW1 5AB" into a sign-up form. The string has no comma after the flat, missing punctuation, and Camden is the borough rather than the post town. A direct lookup against AddressBase fails. A fuzzy address-matcher resolves it to UPRN 5048291734 with a confidence of 0.92, drops the borough, and rewrites the post town to LONDON. Without that step the record either stays unmatched or, worse, joins to the wrong flat in the same building — common in mansion blocks where flat numbers run 1–80.
Related questions
Can I find a UPRN from a postcode alone?
A postcode covers anywhere from one property to roughly 100, so it cannot resolve to a single UPRN. What it can do is return the candidate list. Homedata's UPRN Lookup accepts postcode input and returns every UPRN within it, with the address line for each, letting the user pick. For bulk reverse lookups (give me every UPRN in CR0 1XX), the OS Open UPRN dataset joined to OS Open Names handles it offline.
What if my address has no UPRN?
Almost every addressable object in Great Britain has one — over 41 million UPRNs are live. If a search returns nothing, the most likely cause is a brand-new build still on a "Plot" record, an unusual sub-property (HMO bedroom, mooring, mast) not yet split out, or a Northern Ireland address (UPRNs cover GB; NI uses a separate system run by Land and Property Services). Submit a missing-address request to your local authority street naming team and they will allocate one within a few weeks.
Sources
Related reading
Building with UK property data?
Homedata returns 29 million UK properties — UPRN, EPC, Land Registry, risk — keyed by a single ID. Free tier, no card.
Get a free API key