> For the complete documentation index, see [llms.txt](https://docs.os.uk/osngd/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/osngd/data-structure/address/address-related-components.md). # Address Related Components ## What are related components? The address related components provide supplementary non-geospatial information or context about addresses. ### Addressable object related components There are three addressable object related components in the OS NGD Address Theme; they can be linked to a local authority address record in a feature type using the Unique Property Reference Number (UPRN) as the foreign key. Data schema version 3.0 onward of the Built Address, Historic Address, Non-Addressable Object and Pre-Build Address Feature Types in the OS GB Address and OS Islands Address Collections are supported by the three addressable object related components: * [**Alternate Address**](/osngd/data-structure/address/address-related-components/alternate-address.md): These provide alternative address labels where they exist for the ‘current’ address represented on a given feature type. * [**Other Classification**](/osngd/data-structure/address/address-related-components/other-classification.md): These provide additional Valuation Office Agency (VOA) classification information. * [**Related Entity**](/osngd/data-structure/address/address-related-components/related-entity.md): These contain cross-reference relationship information between addresses and features in other OS NGD themes (such as buildings, sites, roads and boundaries) or third-party data sets. ### :new: Royal Mail related components There are three Royal Mail related components in the OS NGD Address Theme; they can be linked to an address record in a feature type using the Unique Delivery Point Reference Number (UDPRN) as the foreign key. Data schema version 2.0 onward of the Royal Mail Address Feature Type in the OS GB Address and OS Islands Address Collections is supported by the three Royal Mail related components: * [**Multiple Residence**](/osngd/data-structure/address/address-related-components/multiple-residence.md): These provide data developed to identify addresses that are delivered to a shared delivery point; this means premises with one front door, or delivery point, that has been subdivided into flats, units or other separate occupancies. Multiple residence data provide a detailed address structure for these properties. * [**Delivery Point Alias**](/osngd/data-structure/address/address-related-components/delivery-point-alias.md): These provide alias data related to a delivery point address, sourcing data from Royal Mail's Delivery Point Alias (DPA) table. DPA information provides additional Delivery Point Information, including Trading Names and Building Name details where a Building Number is the official building identifier. * [**Other Alias**](/osngd/data-structure/address/address-related-components/other-alias.md): These provide alternate names for counties, localities and thoroughfares. {% hint style="info" %} **Delivery Point Alias and Other Alias Related Component tables will be empty initially** Please note that the Delivery Point Alias and Other Alias Related Component tables are included in product design for future compatibility but are not currently populated; customers should expect these files to be empty until a future data enhancement enables OS to supply the Royal Mail alias data. Please see the [FAQs](/osngd/getting-started/faqs.md#why-are-the-other-alias-and-delivery-point-alias-related-component-tables-in-my-royal-mail-address-f) for more information. {% endhint %} ### :arrows\_clockwise: Data structure The OS NGD Address Theme data structure diagram below is applicable to the **latest data schema versions** of all address feature types, that is data schema version 3.0 of Built Address, Historic Address, Non-Addressable Object and Pre-Build Address, data schema version 1.0 of Street Address, and data schema version 2.0 of Royal Mail Address:
OS NGD Address Theme data structure diagram showing the theme name, collection names, feature type names, and related component names. The data structure diagram is applicable to the latest data schema versions of all address feature types.

OS NGD Address Theme data structure diagram showing the theme name, collection names, feature type names, and related component names; it's applicable to the latest data schema versions of all address feature types.

Please see [Data schema versioning](/osngd/getting-started/os-ngd-fundamentals/data-schema-versioning.md) for information on data schema versioning in the OS NGD. [Superseded data structure diagrams for the OS NGD Address Theme](/osngd/data-structure/address.md#data-structure) are available on the OS NGD Address Theme page. {% hint style="warning" %} ## Postal Address Related Component * Until September 2025, [Postal Address Related Component](/osngd/data-structure/address/address-related-components/postal-address.md) was the fourth related component in the OS NGD. It has been discontinued in the latest data schema version 3.0 of the Built Address, Historic Address, Non-Addressable Object and Pre-Build Address Feature Types in the OS GB Address and OS Islands Address Collections, which released in September 2025. * The Postal Address Related Component contained delivery point data from the Royal Mail Postcode Address File (PAF). This information is now available in the Royal Mail Address Feature Type (which launched in September 2025), which can be found in the [OS GB Address](/osngd/data-structure/address/gb-address.md) and [OS Islands Address](/osngd/data-structure/address/islands-address.md) Collections. * The Postal Address Related Component is still provided against the older (maintenance) data schema versions 1.0 and 2.0 of the Built Address, Historic Address, Non-Addressable Object and Pre-Build Address Feature Types in the OS GB Address and OS Islands Address Collections. These data schema versions are available for customers to use, but they are now older and in maintenance mode. (Data schema version 3.0 is the latest and recommended data schema version to use for these feature types.) {% endhint %} ## :arrows\_clockwise: When will related components be provided? {% hint style="success" %} Related components will **always be provided** if you have chosen to receive any of the five following feature types from the OS NGD Address Theme: * Built Address, Historic Address, Non-Addressable Object or Pre-Build Address; the primary identifier for these four feature types is the URPN (Unique Property Reference Number). * Royal Mail Address data schema version 2.0 onward if the Description attribute is down as 'Postcode Address File'. When the Description attribute is down as 'Not Yet Built' for Royal Mail Address Feature Type data schema version 2.0 onward, you will be provided with related components, but they will be 'Null'. The primary identifiers to associate the related component tables to the Royal Mail Address Feature Type are the Royal Mail's Unique Delivery Point Reference Number (UDPRN) and Unique Multiple Residence Reference Number (UMRRN). {% endhint %} {% hint style="warning" %} * Related components **will not be provided** for the Street Address Feature Type as its primary identifier is Unique Street Reference Number (USRN), not UPRN, UDPRN or UMRRN. * Related components **will not be provided** for Royal Mail Address Feature Type data schema version 1.0 and 1.1. (The three Royal Mail related components were added to this feature type from data schema version 2.0 onward.) {% endhint %} ## :arrows\_clockwise: How to handle related components The related components do not contain geometry and therefore need to be joined to the relevant feature type table using: * UPRN for the Built Address, Historic Address, Non-Addressable Object and Pre-Build Address Feature Types * UDPRN or UMRRN for the Royal Mail Address Feature Type data schema version 2.0 onward When data is supplied, you will receive related component data split out by feature type. For example, customers taking data schema version 1.0 or 2.0 of the Pre-Build Address Feature Type in GeoPackage format will receive: * Feature type: Pre-Build Address * Related component: Pre-Build Alternate Address * Related component: Pre-Build Postal Address * Related component: Pre-Build Related Entity * Related component: Pre-Build Other Classification For example, customers taking data schema version 3.0 of the Pre-Build Address Feature Type in GeoPackage format will receive: * Feature type: Pre-Build Address * Related component: Pre-Build Alternate Address * Related component: Pre-Build Related Entity * Related component: Pre-Build Other Classification :new: For example, customers taking data schema version 2.0 of the Royal Mail Address Feature Type in GeoPackage format will receive: * Feature type: Royal Mail Address * Related component: Multiple Residence * Related component: Delivery Point Alias * Related component: Other Alias --- # Agent Instructions This documentation is published with GitBook. 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