> For the complete documentation index, see [llms.txt](https://docs.os.uk/os-downloads/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.os.uk/os-downloads/products/addresses-and-names-portfolio/addressbase-core/addressbase-core-technical-specification.md). # AddressBase Core Technical Specification AddressBase Core is a simple, accessible addressing data product giving Plug and Play access to Great Britain addressing data and additional attribution, without being time-consuming or complex. It provides live addressing records for England, Wales and Scotland based on Local Authority holdings of the Local Land and Property Gazetteer (LLPG). Other attribution includes secondary level classifications (detailing the use and type of an address) and a representative point code describing the positional quality of coordinates. This technical specification includes the following sections: * [Data formats](/os-downloads/products/addresses-and-names-portfolio/addressbase-core/addressbase-core-technical-specification/data-formats.md) * [Supply and update](/os-downloads/products/addresses-and-names-portfolio/addressbase-core/addressbase-core-technical-specification/supply-and-update.md) * [Attributes](/os-downloads/products/addresses-and-names-portfolio/addressbase-core/addressbase-core-technical-specification/attributes.md) * [Enumerations](/os-downloads/products/addresses-and-names-portfolio/addressbase-core/addressbase-core-technical-specification/enumerations.md) * [Example records](/os-downloads/products/addresses-and-names-portfolio/addressbase-core/addressbase-core-technical-specification/example-records.md) Additional documentation covering the complete family of AddressBase products is available in the AddressBase Fundamentals pages. These covers key elements of design for AddressBase products, including: * [Future and past publication dates](/os-downloads/products/addresses-and-names-portfolio/addressbase-fundamentals/future-and-past-publication-dates.md) * [Unique Property Reference Number (UPRN)](/os-downloads/products/addresses-and-names-portfolio/addressbase-fundamentals/unique-property-reference-number-uprn.md) * [Coordinate reference systems](/os-downloads/products/addresses-and-names-portfolio/addressbase-fundamentals/coordinate-reference-systems.md) * [Classification scheme](/os-downloads/products/addresses-and-names-portfolio/addressbase-fundamentals/classification-scheme.md) * [Data sources](/os-downloads/products/addresses-and-names-portfolio/addressbase-fundamentals/data-sources.md) * [Street names and numbering](/os-downloads/products/addresses-and-names-portfolio/addressbase-fundamentals/street-names-and-numbering.md) * [Currency completeness and precision](/os-downloads/products/addresses-and-names-portfolio/addressbase-core/addressbase-core-overview/currency-completeness-and-precision.md) * [Product supply](/os-downloads/products/addresses-and-names-portfolio/addressbase-fundamentals/product-supply.md) * [AddressBase local custodian codes](/os-downloads/products/addresses-and-names-portfolio/addressbase-fundamentals/addressbase-local-custodian-codes.md) * [AddressBase Islands local custodian codes](/os-downloads/products/addresses-and-names-portfolio/addressbase-fundamentals/addressbase-islands-local-custodian-codes.md) --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://docs.os.uk/os-downloads/products/addresses-and-names-portfolio/addressbase-core/addressbase-core-technical-specification.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.