A Local Land and Property Gazetteer (LLPG) is the definitive, centrally managed list of all addresses and land parcels within a local authority's area in the United Kingdom. Maintained by each council, it acts as the single, trusted source of address data for that locality and feeds directly into the National Address Gazetteer (NAG), which is the country's official master address dataset. The LLPG is a cornerstone of local government operations and a vital resource for anyone researching a specific area.
What is a Local Land and Property Gazetteer?
An LLPG is more than just a list of streets and house numbers. It is a comprehensive database that records every property, from residential homes and commercial buildings to land parcels and public amenities. Each entry is assigned a unique property reference number (UPRN), which stays with the property for its entire life, even if the address or postcode changes. The gazetteer is built and maintained by the local authority's street naming and numbering team, working in partnership with the Royal Mail, Ordnance Survey, and other bodies to ensure accuracy. It includes detailed information such as the official address (including postcode), geographic coordinates, land use classification, and building status. The LLPG is continuously updated to reflect new builds, demolitions, conversions, and changes to street names or numbering.
How the LLPG fits into the UK address and postcode system
The LLPG sits at the local level of the UK's address infrastructure. It is the primary source from which address data flows upward into national databases. The National Address Gazetteer (NAG) is the aggregation of all LLPGs from every council in England and Wales, plus equivalent datasets from Scotland and Northern Ireland. This creates a seamless, nationwide address dataset that underpins services such as emergency response, utility mapping, and mail delivery. In terms of postcodes, the LLPG does not create postcodes; that is the role of Royal Mail. However, the LLPG records the official postcode for each property as assigned by Royal Mail. When a new property is built, the local authority assigns a street name and number, then notifies Royal Mail, which allocates a postcode. This postcode is then entered into the LLPG. Conversely, if Royal Mail changes a postcode, the LLPG is updated to reflect it. The LLPG thus forms the bridge between the physical address and the postcode, ensuring that every postcode is linked to a precise, verified location.
Relationship with the National Address Gazetteer
The National Address Gazetteer relies on LLPGs being accurate and up to date. Each council submits its LLPG data to the GeoPlace partnership, which manages the NAG. This national dataset is then used by Ordnance Survey to produce products such as AddressBase, which combines address data with topographic mapping. For postcode users, this means that when you look up a postcode online, the address information you see ultimately originates from the LLPG maintained by the relevant council. The LLPG ensures consistency: the same property has the same address and postcode in every official system.
Why the LLPG matters to someone researching an area
For anyone conducting research into a specific location - whether for property buying, planning applications, demographic studies, or historical analysis - the LLPG is an invaluable resource. Because it is the authoritative record, you can rely on it for accurate address data. For example, if you are investigating a neighbourhood, the LLPG can tell you exactly which properties exist, their official addresses, and their postcodes. It can reveal whether a property has been subdivided or merged, or if a new development has been built. Researchers can also use the UPRN to track a property through time, as the number remains constant even if other details change. Councils often make LLPG data available through open data portals or address lookup tools, enabling you to verify addresses, check postcode boundaries, or understand the land use mix in an area. In summary, the LLPG is the bedrock of address information in the UK, and understanding it gives you confidence in the accuracy of any address or postcode data you use for your research.