Open Identifiers policy

This is OS’s Open Identifiers Policy, and is published as part of our OS Open MasterMap Implementation Programme, which delivers some of our obligations under the Public Sector Geospatial Agreement (PSGA) between OS and the Geospatial Commission, part of the Department of Science, Innovation and Technology.

This Open Identifiers Policy replaces our previous Topographic Identifier (TOID) and Unique Property Reference Numbers (UPRN) policies  with a single, unified policy for OS TOIDs, UPRNs and Unique Street Reference Numbers (USRNs).

The policy is aimed at enabling the widest possible use and sharing of TOIDs, UPRNs and USRNs, feeding valuable data into the geospatial ecosystem.

Accordingly, we make TOIDs, UPRNs and USRNs available under the terms of the Open Government Licence (OGL) in certain Open Products and Services, as described in section 1 below (“Open Products and Services”).

In addition, we permit certain customers the right to publish TOIDs, UPRNs and USRNs on OGL terms, where these identifiers are obtained from OS premium products and services, provided this is done in line with the policy conditions as described in section 2 below (“The Open Identifiers Policy in relation to Premium products and services”).

OS makes TOIDs, UPRNs, and USRNs available on the terms of the Open Government Licence (OGL), as part of the following Open Products:

• OS Open UPRN:
  A dataset containing all Unique Property Reference Numbers (UPRNs) and geometry from AddressBase Premium. This includes UPRNs for features such as residential and commercial dwellings, ponds, electricity substations and advertising hoardings. It is synchronised with AddressBase Premium in completeness and currency.

• OS Open USRN:
  A dataset containing all Unique Street Reference Numbers (USRNs) from OS MasterMap Highways Network, with a simplified line geometry. It is synchronised with OS MasterMap Highways Network in completeness and currency.

• OS Open TOID:
  A dataset containing TOIDs and a generalised XY coordinate for all buildings, structures, land cover and transport infrastructure from OS MasterMap, and as well as metadata. It is synchronised with OS MasterMap Topography Layer in completeness and currency.

• OS Open Linked Identifiers: 
  A dataset containing the relationship between UPRNs, USRNs and TOIDs, and metadata.

OS also makes TOIDs, UPRNs, and USRNs available as part of the following premium products and services on OS’s standard licence terms:

• OS MasterMap Topography Layer
• OS MasterMap Sites Layer
• OS MasterMap Highways Network
• OS MasterMap Highways Network – Roads
• OS MasterMap Highways Network – Roads and Routing and Asset Management Information
• OS MasterMap Highways Network – Paths
• OS MasterMap Highway Road Network with Routing and Asset Management Information and Average Speed
• OS MasterMap Highways Road Network with Routing and Asset Management Information and Speed Limits
• OS MasterMap Highways Road Network with Routing and Asset Management Information and Average Speed and Speed Limits
• OS MasterMap Water Network
• OS MasterMap Greenspace
• AddressBase
• AddressBase Core
• AddressBase Plus
• AddressBase Premium
• OS Features API
• OS Vector Map Tiles API
• OS Places API (excluding AddressBase Islands Transactions relating to Northern Ireland, Channel Islands or Isle of Man)
• OS Match & Cleanse API (excluding AddressBase Islands Transactions relating to Northern Ireland, Channel Islands or Isle of Man)

The policy applies to (i) public sector organisations licensed under the PSGA Member Licence, and (ii) internal business users¹, to the extent that your licence states that you are entitled to benefit from this policy.² 

OS permits applicable end users to sub-license TOIDs, UPRNs, USRNs and associated version numbers, on the terms of the OGL, provided that the relevant TOID, UPRN and USRN are:

• Appended to data owned by the end user; and/or
• Appended to open data; and/or
• Appended by a public sector organisation to data that is exempt data pursuant to clause 2.6 of the PSGA Member Licence (for further details, see PSGA licensing guidance on exempt data; and/or
• Appended to a commercially licensed dataset (that has appropriate terms in place to allow the applicable end user to do so).

Yes, applicable end users must use an attribute from the OS Open ID Green List to match the TOIDs, UPRNs or USRNs to their dataset; these attributes are summarised in the bullet points below:

• Feature Geometry (e.g. X, Y coordinates);
• Feature Names (e.g. Address String components);
• All identifiers associated to features (e.g. UDPRN, gssCodes);
• Feature categorisation for OS MasterMap Topography Layer only.
• Any other attribute type identified in the exhaustive ‘OS Open ID Green List’ 

To be clear, attributes listed on the OS Open ID Green List can be used in matching TOIDs, UPRNs or USRNs as described above, but cannot be made available on the term of the OGL.

Note that the OS Open ID Green List attribution should only be used for matching to another dataset which already has the same attribute present (and which, by way of reminder, must also be one of the four types of dataset described in the section above).

Attributes listed on the OS Open ID Green List can be used in matching TOIDs, UPRNs or USRNs as described above, but cannot be made available on the term of the OGL.

Note that the OS Open ID Green List attribution should only be used for matching to another dataset which already has the same attribute present (and which, by way of reminder, must also be one of the four types of dataset described in the section above).

In addition, nothing in this policy shall permit the end user to (and the end user shall ensure that no sub-licensee shall) re-create, reproduce or represent any attribute from the OS Open ID Green List. For example, it would not be permissible to make available UPRNs with a building number of 1, or UPRNs with a building number of 2, as this would enable reverse engineering of a premium attribute (i.e. the house number).

^{[1] Relevant terms are included by OS in its Framework Contract (Direct Customers) and, in addition, OS’s Licensed Partners are obliged to pass on the benefit of this policy to end users licensed for “internal business use” under the Distribution Contract, the Business Solutions – Online Viewing Contract, the Business Solutions – Data Component Contract, and the OS API Service Terms.}

^{[2] This policy does not apply to licensees to the extent they are using data for trial and testing and/or development activities (as opposed to use in the internal administration of their business), e.g. under the Data Exploration Licence (DEL), “trial and test” terms granted by an OS Licensed Partner, or use in Development Mode under the OS API Service Terms.}