The Unique Property Reference Number (UPRN) is a twelve-digit identifier assigned to every addressable location in Great Britain. It is maintained by Ordnance Survey as part of the AddressBase product, which provides a definitive list of all addresses in the country. Unlike a postcode, which covers a group of addresses, a UPRN is unique to a single property, making it a highly precise reference for any location.

What is a UPRN?

Each UPRN is a permanent, unique number that stays with a property even if its address or postcode changes. It covers not just residential homes but also commercial premises, public buildings, and even non-addressable features like bus shelters or utility substructures. Ordnance Survey derives UPRNs from multiple sources, including local authorities and Royal Mail, and ensures they remain consistent over time. The AddressBase dataset links UPRNs to coordinates (eastings and northings), postcodes, and other address elements, forming the backbone of many geographic information systems.

Relationship to Postcodes and Addresses

While a postcode typically identifies a group of up to about 100 addresses, a UPRN pinpoints a single building. For example, two flats in the same block may share a postcode but each has its own UPRN. This granularity allows UPRNs to be used alongside postcodes for more accurate data matching. In practice, organisations often link postcodes to UPRNs to get the best of both worlds: the broad geographic grouping of a postcode and the exact location of a UPRN. The Royal Mail’s Postcode Address File (PAF) does not include UPRNs, so mapping between the two systems requires Ordnance Survey data.

Importance for Area Research

For someone researching an area, UPRNs enable precise identification of individual properties over time. They facilitate linking data from different sources such as census records, council tax registers, and utility databases without ambiguity. When analysing demographic changes, property values, or service coverage, UPRNs provide a stable reference point even if street names or postcodes are reorganised. Researchers can track how a specific building is used, whether it has been demolished or replaced, and integrate information across years. Because UPRNs are geographically referenced, they also allow spatial analysis at the building level, offering finer detail than postcode-based studies. In summary, the UPRN is a fundamental element for anyone needing accurate, persistent location data in the UK.

  • It is a unique identifier, not a location code like a postcode.
  • It remains constant regardless of address or administrative changes.
  • It supports precise data linkage and historical research.