AddressBase is Ordnance Survey's definitive address product, providing a comprehensive and accurate database of all addresses in Great Britain. It links each address to a Unique Property Reference Number (UPRN), precise coordinates (eastings and northings), the postcode, and records from local authorities. This makes it the single most authoritative source for address data in the UK, used by government, businesses and the public sector for a wide range of applications.
What is AddressBase?
AddressBase is not just a simple list of addresses; it is a sophisticated geospatial dataset. Every residential, commercial and public building is assigned a UPRN, which acts as a persistent identifier throughout the property's lifecycle. The dataset includes the full address written in Royal Mail's Postcode Address File (PAF) format, the postcode itself, and the Ordnance Survey grid reference. It also incorporates local authority information such as the local council, ward, and parliamentary constituency boundaries. AddressBase is updated daily to reflect new builds, demolitions, and changes to street names or postcodes, ensuring it remains current and reliable.
How AddressBase Relates to Postcodes and Addresses
The relationship between AddressBase and postcodes is fundamental. While the postcode is a key element of an address, AddressBase goes far beyond by providing a precise geographic location for every address within that postcode. For example, a single postcode may cover a block of flats or a row of shops; AddressBase assigns a unique UPRN and coordinates to each individual unit, allowing for granular analysis. The dataset also cross-references with Royal Mail's PAF, but adds value by including properties that do not receive mail (such as substations or telephone exchanges) and by providing the authoritative spatial reference. For anyone researching an area, this means you can look up a postcode and immediately see every address within it, along with its exact location on a map, its local authority, and its property type (e.g., detached house, flat, or commercial premises).
AddressBase in the UK Geography System
AddressBase sits at the heart of the UK's geographic information infrastructure. It is a core component of Ordnance Survey's MasterMap product, which provides a detailed digital map of the country. AddressBase is used by emergency services to locate incidents quickly, by local councils to manage council tax and electoral registers, and by utility companies to plan network connections. It also underpins many online mapping services and property websites, enabling users to search by postcode or address and see accurate locations. For researchers, AddressBase is invaluable because it links to other datasets such as census output areas, lower layer super output areas (LSOAs), and health geographies. This allows for demographic analysis at the individual address level, while preserving privacy through aggregation.
Why AddressBase Matters for Area Research
If you are researching an area, AddressBase provides the foundational layer for understanding its built environment. You can identify the density of residential versus commercial properties, map the distribution of different property types, and analyse how addresses relate to transport links, green spaces, or flood zones. Because each address has a UPRN, you can track changes over time, such as new housing developments or conversions. The dataset also enables you to assign addresses to specific administrative areas, such as wards or parliamentary constituencies, which is essential for electoral studies or local government analysis. In short, AddressBase turns a simple postcode or address into a rich, geospatially precise data point that can be combined with countless other sources to build a detailed picture of any location in Great Britain.