# OS Open Linked Identifiers Documentation

An open dataset of cross-referenced identifiers between various OS data products.

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**This product is updated every six weeks.**
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<figure><img src="https://1897589978-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FcNpJpLP8RROUaWVQo5ea%2Fuploads%2Fl7KmBJ1ATF2KiqfuMrwZ%2Fimage.png?alt=media&#x26;token=ca20585c-27b6-4400-ae59-068c4bf41326" alt="Example of OS Open Linked Identifiers data displayed against a background map"><figcaption><p>Example of OS Open Linked Identifiers data displayed against a background map</p></figcaption></figure>

OS Open Linked Identifiers provides authoritative relationship between Unique Property Reference Numbers (UPRNs), Unique Street Reference Numbers (USRNs), Topographic Object Identifiers (TOIDs) and metadata to enable reliable matching and for greater data connectivity.

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OS Open Linked Identifiers is part of the OS Open Identifiers 'Family' of products, which includes four OpenData products: OS Open Linked Identifiers, OS Open TOID, OS Open UPRN and OS Open USRN. The products within this family allow you to easily share information held against a range of identifiers and to link together information associated with these identifiers.
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**Relationships between UPRNs, USRNs and TOIDs**

OS Open Linked Identifiers is a dataset containing the authoritative relationships between UPRNs, USRNs and TOIDs.

**Better visualisation**

Connecting addresses with road features enables more related data to be joined together which simplifies a number of valuable workflows. Linking these features to graphical elements of OS MasterMap products enables better visualisation of the data related to them.

**Find all addresses on a road**

Link data related to an address with its building footprint. Validate an address's UPRN with the name of the road that accesses it. Validate a street's USRN with the name of the road it relates to.

**Authoritative source**

The relationships UPRN and USRN are provided by the bodies responsible for the identifier schemes, and these are spatially matched to OS MasterMap features by Ordnance Survey. This means you can have confidence that you're accessing an authoritative source of these relationships.

**Relationships you can trust**

The relationships are taken from our Premium Download data products and made open so that everyone can access them from one trusted source.

OS Open Linked Identifiers provides the relationships between the following features found in OS MasterMap products (note that Topographic Areas are limited to address and road features):

* **TopographicArea\* (TOID):** OS MasterMap Topographic Layer
* **RoadLink(TOID):** OS MasterMap Highways Networks – Roads
* **Road(TOID):** OS MasterMap Highways Networks – Roads
* **ORRoadLink/ORRoadNode(GUID):** OS Open Roads
* **Street(USRN):** OS MasterMap Highways Networks – Roads
* **BLPU(UPRN):** AddressBase Premium

\*restricted to address and road features.
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{% tab title="Summary" %}

* **Access:** Download via the [OS Data Hub](https://osdatahub.os.uk/)
* **Data theme:** Multiple
* **Data structure:** Vector – Identifiers
* **Coverage:** Great Britain
* **Scale:** 1:1 250 to 1:10 000
* **Format:** CSV
* **Ordering area:** All of Great Britain
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**Identifier version information**

Open Linked Identifiers includes the latest version information for all the respective features that are referred to. In some cases, this might be a different version of the feature than what was used to form the relationship. This means that in some cases the relationship might not still be valid. To help resolve this we’ve also included a confidence value, indicating if the feature has changed since the relationship was formed, which can be used to resolve errors.

**Geometry and attribution access**

Geometry is not included in OS Open Linked Identifiers. You can get the geometry you need from either [OS Open UPRN](https://docs.os.uk/os-downloads/products/addresses-and-names-portfolio/os-open-uprn), [OS Open USRN](https://docs.os.uk/os-downloads/products/transport-network-portfolio/os-open-usrn) or [OS Open TOID](https://docs.os.uk/os-downloads/products/buildings-and-infrastructure-portfolio/os-open-toid).

**UDPRN**

OS Open Linked Identifiers does not contain UDPRNs (Unique Delivery Point Reference Numbers), as there is third party IP associated with UDPRNs.
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## How to get this product

Access to this OS OpenData product is free through the [OS Data Hub](https://osdatahub.os.uk/data/downloads/open/LIDS).

## What's next?

To access additional documentation and resources relating to this product, please refer to the following:

<table data-view="cards"><thead><tr><th></th><th></th><th data-hidden data-card-cover data-type="image">Cover image</th><th data-hidden data-card-target data-type="content-ref"></th></tr></thead><tbody><tr><td><h4>OS Open Identifiers Family Information</h4></td><td>This page gives context and information about the OS Open Identifiers 'Family' of products, including explaining what identifiers are and introducing the OS identifiers (TOID, UPRN and USRN).</td><td data-object-fit="cover" data-alt="OS Open Linked Identifiers diagram showing the interconnected relationship in the product between TOIDs, UPRN, USRNs, and GUID."><a href="https://1897589978-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FcNpJpLP8RROUaWVQo5ea%2Fuploads%2FevuHYX9cyID9OYhzPVGe%2FLinked_identifiers_Cover.avif?alt=media&#x26;token=5d07dde3-8aeb-4930-9526-e5d5487c8306">Linked_identifiers_Cover.avif</a></td><td><a href="../addresses-and-names-portfolio/os-open-uprn/os-open-uprn-overview/what-is-an-identifier">what-is-an-identifier</a></td></tr><tr><td><h4>Overview</h4></td><td>The overview introduces OS Open Linked Identifiers and gives context for all users – highlighting key features, giving examples of potential uses, and listing details on file sizes, supply formats, etc.</td><td data-object-fit="cover" data-alt="OS Open Linked Identifiers diagram showing the interconnected relationship in the product between TOIDs, UPRN, USRNs, and GUID."><a href="https://1897589978-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FcNpJpLP8RROUaWVQo5ea%2Fuploads%2FevuHYX9cyID9OYhzPVGe%2FLinked_identifiers_Cover.avif?alt=media&#x26;token=5d07dde3-8aeb-4930-9526-e5d5487c8306">Linked_identifiers_Cover.avif</a></td><td><a href="os-open-linked-identifiers/os-open-linked-identifiers-overview">os-open-linked-identifiers-overview</a></td></tr><tr><td><h4>Getting Started Guide</h4></td><td>The getting started guide provides instructions for using OS Open Linked Identifiers in different software applications. Users with limited technical knowledge will be able to follow this guide.</td><td data-object-fit="cover" data-alt="Example image showing OS Open Linked Identifiers product data over a background map."><a href="https://1897589978-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FcNpJpLP8RROUaWVQo5ea%2Fuploads%2FoXsZRIVyNwVtFMP0Forj%2F5_LIDS_topo_area_uprn.png?alt=media&#x26;token=cf27bc32-62f2-48fc-b775-b3db4d5a6e0c">5_LIDS_topo_area_uprn.png</a></td><td><a href="os-open-linked-identifiers/os-open-linked-identifiers-getting-started-guide">os-open-linked-identifiers-getting-started-guide</a></td></tr><tr><td><h4>Technical Specification</h4></td><td>The technical specification provides detailed technical information about OS Open Linked Identifiers. It is targeted at technical users and software developers.</td><td data-object-fit="cover" data-alt="Example image showing OS Open Linked Identifiers product data over a background map."><a href="https://1897589978-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FcNpJpLP8RROUaWVQo5ea%2Fuploads%2FfjpDAJkjlDnMq2C1ee4C%2F9_LIDS_UPRN_addressbase.png?alt=media&#x26;token=d0c5e533-9574-43b5-a1b0-af11cb74dac1">9_LIDS_UPRN_addressbase.png</a></td><td><a href="os-open-linked-identifiers/os-open-linked-identifiers-technical-specification">os-open-linked-identifiers-technical-specification</a></td></tr><tr><td><h4>Ordnance Survey Website</h4></td><td>View OS Open Linked Identifiers product information and find out how to get this product on the OS website.</td><td></td><td><a href="https://www.ordnancesurvey.co.uk/products/os-open-linked-identifiers">https://www.ordnancesurvey.co.uk/products/os-open-linked-identifiers</a></td></tr></tbody></table>

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New users should start with the Overview to gain high-level insights into the product. The Getting Started Guide will help you to begin using product data in different software systems. The Technical Specification contains detailed technical insights.

We recommend referring to the OS Open Identifiers Family Information page in combination with the Overview and Technical Specification documents for OS Open Linked Identifiers.
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