A UPRN — Unique Property Reference Number — is a numeric ID assigned to every addressable location in Great Britain: houses, flats, garages, even individual parking spaces. It's maintained as part of Ordnance Survey's AddressBase dataset and used across local government and utilities as the definitive way to refer to a single property, independent of how its address happens to be written.
Unlike a postcode, which covers a group of neighbouring addresses, a UPRN identifies exactly one property. And unlike an address, it doesn't change if a street is renamed, a building is renumbered, or a postcode boundary shifts — the UPRN stays the same for the life of the property.
On a Rigove property page, the UPRN shown comes from one of three places, noted alongside it: an account managing a link on that listing entered it directly (self-reported, not independently verified); it was matched automatically from the listing's stated postcode against the Ordnance Survey's official UPRN dataset; or that automatic match came back ambiguous and a person resolved it by hand against the real address. The middle two are more reliable than a self-report, but none of them is a substitute for checking the listing details yourself.
The UPRN links through to propertypassport.uk, a free lookup built on official UK government registers — HM Land Registry, the EPC Register, the Environment Agency, Ordnance Survey, Historic England and the GOV.UK planning data platform among them. Search a UPRN there and, free, you'll typically see the property's last sale price and date, its current EPC energy rating, a flood risk screening, its recorded tenure, and its floor area — plus a headline risk score across categories like flood, ground conditions, structural, title, energy, planning and location, each flagged for you to look into further. It isn't a survey or a formal valuation, but it's a genuinely useful first pass before you go further — worth a look for any property you're seriously considering, not just the ones where something already looks off.