OS Open TOID | Data Products | OSOrdnance Survey

This open dataset shows unique identifiers for a wide range of landscape and built environment features with a generalised location extracted from OS MasterMap products. A TOID (Topographic Identifier) is a unique and persistent identifier for each and every feature found in OS MasterMap products.

How to get this product

Access to this OS OpenData product is free through the OS Data Hub.

What's next?

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

OS Open Identifiers Family Information

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).

Overview

The overview introduces OS Open TOID and gives context for all users – highlighting key features, providing examples of potential uses, and listing details such as supply formats, currency, etc.

Technical Specification

The technical specification provides detailed technical information about OS Open TOID. It is targeted at technical users and software developers.

OS Open TOID – January 2025 release note

This release note provides information about the January 2025 (Epoch 40) release of OS Open TOID.

OS Open TOID – November 2024 release note

This release note provides information about the November 2024 (Epoch 39) release of OS Open TOID.

OS Open TOID – September 2024 release note

This release note provides information about the September 2024 (Epoch 38) release of OS Open TOID.

OS Open TOID – August 2024 release note

This release note provides information about the August 2024 (Epoch 37) release of OS Open TOID.

OS Open TOID – July 2024 release note

This release note provides information about the July 2024 (Epoch 36) release of OS Open TOID.

OS Open TOID Release Note January 2025 (Epoch 40)

Feature counts

Feature counts for this release are provided in the following table:

There are no missing features and no duplicated TOIDs in this release. No significant errors have been identified.

Next Release

The next release of OS Open TOID (Epoch 40), is scheduled for 14 February 2025.

Feature counts

Feature counts for this release are provided in the following table:

There are no missing features and no duplicated TOIDs in this release. No significant errors have been identified.

Next Release

The next release of OS Open TOID (Epoch 40), is scheduled for 06 January 2025.

Feature counts

Feature counts for this release are provided in the following table:

There are no missing features and no duplicated TOIDs in this release. No significant errors have been identified.

Next release

The next release of OS Open TOID (Epoch 39), is scheduled for 15 November 2024.

Feature counts

Feature counts for this release are provided in the following table:

There are no missing features and no duplicated TOIDs in this release. No significant errors have been identified.

Next release

The next release of OS Open TOID (Epoch 38) is scheduled for 04 October 2024.

Feature counts

Feature counts for this release are provided in the following table:

There are no missing features and no duplicated TOIDs in this release. No significant errors have been identified.

Next release

The next release of OS Open TOID (Epoch 37), is scheduled for 23 August 2024.

OS Open TOID is an open dataset of unique identifiers – Topographic Identifiers (TOIDs) – assigned by OS to real-world features extracted from the following three OS MasterMap products:

• OS MasterMap Topography Layer

  • TopographicArea

  • TopographicLine

  • TopographicPoint

• OS MasterMap Sites Layer

  • SiteExtent

• OS MasterMap Highways Network – Roads

  • RoadNode

  • RoadLink

  • PathLink

This product allows users to share and link information related to a wide range of landscape and built environment features with a unique identifier and generalised location which will allow them to be used easily by everyone.

OS Open TOID provides the identifiers for these features along with their generalised location:

• Point features: The original location rounded to the nearest metre.

• Line features: The midpoint of the line rounded to the nearest metre.

• Polygons features: Use a point of inaccessibility algorithm to find a point that is guaranteed to be within the polygon which is farthest from all edges; this location is then rounded to the nearest metre.

• Multi-polygon features (SiteExtent): Use the same method as for polygon features on the largest of the polygons.

Key features

The key features of the OS Open TOID product are:

• The comprehensive inclusion of all Ordnance Survey’s capture of the physical features across Great Britain.

• Access to our unique topographic identifiers, allowing you to link to the OS MasterMap products.

• A guide to which products the features are sourced from.

• The ability to reference between a feature and qualitative data using a unique identifier.

Product applications

OS Open TOID offers a range of opportunities to link and share disparate datasets against a unique identifier, with a location.

For example, a local authority may use OS Open TOID to link unaddressed buildings captured within OS MasterMap Topography Layer with information such as ownership or planning permission to build a richer picture of land and property in their remit.

OS Open TOID is a dataset that is designed to use the OS MasterMap product family as a basis with which you can create your own rich, comprehensive dataset that caters to your specific needs. It is not designed to be used as a geospatial selector for features.

Index

This overview includes the following sections:

• Product supply

• Coordinate reference system

OS Open TOID provides unique identifiers and generalised coordinates for point, line and polygon features from a range of source products. These features are represented by a single point with associated information attached. Both the GeoPackage and CSV formats contain:

• TOID (unique identifier)

• Source Product (the product the feature can be found in)

• Version Number (indication of how many times the feature has been edited)

• Version Date (when the feature was last updated)

• XY (location derived for the feature)

A JSON (JavaScript Object Notation) file containing version information will also be supplied with the product.

Available formats

The OS Open TOID and associated geometry data are available in 100km tiles and distributed in two formats using British National Grid (BNG) projection:

• GeoPackage (GPKG)

• Comma-separated values (CSV)

These formats allow the data to be easily integrated and ingested with either a GIS application or a database, respectively.

GeoPackage overview

GeoPackage (GPKG) is an open standard data format as defined by the Open Geospatial Consortium (OGC). GeoPackage is designed to be a lightweight format that can contain large amounts of varied and complex data in a single, easy-to-distribute and ready-to-use file.

Please be advised that older versions of GIS software may need updating before being able to display and interact with GeoPackage files.

GeoPackage offers users the following benefits:

• The single file is easy to transfer and offers the end-user a rich experience.

• Attribute names are not limited in length, making it user-friendly.

• The file size limit is very large at 140TB, so lots of data can be easily accommodated (please note that a file size limit may be imposed by the file system to which the file is written).

• It supports raster, vector and database formats, making it a highly versatile solution.

• It is an OGC standard.

• In most cases, it is a plug and play format.

For information on how to open, use and understand a GeoPackage dataset, please refer to our ‘Getting Started with GeoPackage’ guide. Further detailed information on GeoPackage can be taken from the GeoPackage website.

CSV overview

CSV files are a delimited text file that uses commas or other characters to separate individual elements of a feature. It is used to store data, often in the form of a table. These tables can be freely loaded into databases and programs, allowing for the easy loading and updating of data holdings.

The CSV format of OS Open TOID means:

• The first row will contain header information.

• There will be one record per line in each file.

• Fields will be separated by commas.

• No comma will be placed at the end of each row in the file.

• Records will be terminated by Carriage Return / Line Feed.

Supply mechanism

OS Open TOID is supplied as a free online download and is available without registration from the OS Data Hub.

Coverage

This product covers Great Britain.

OS Open TOID and associated geometry data are available in 100km tiles and distributed in two product formats (GeoPackage or CSV) using British National Grid (BNG) projection.

Currency

OS Open TOID will be updated through a Full Supply on a 6-weekly basis (in-line with the OS MasterMap Topography Layer COU (Change-Only Update) releases outlined in the Product Refresh Dates page and will maintain consistency with the OS MasterMap products).

Coordinate reference system

OS Open TOID and its associated geometry data layer use the British National Grid (BNG) coordinate reference system (CRS).

BNG uses the OSGB36 geodetic datum and a single Transverse Mercator projection for the whole of Great Britain. Positions on this projection are described using Easting and Northing coordinates in units of metres. The BNG is a horizontal spatial reference system only; it does not specify a vertical (height) reference system.

Please view A Guide to Coordinate Systems in Great Britain on our More than Maps platform for more information on CRSs.

OS Open TOID is a comprehensive list of the unique identifiers used in our OS MasterMap data alongside the generalised location of the physical feature. The unique identifier used is the TOID (Topographic Identifier) and is commonly found throughout our data allowing for an easy transition between datasets. It consists of the letters ‘osgb’ followed by either 13 or 16 digits between 0 and 9. In order for the TOID to be effective it is essential that the OS appointed TOID reference is not altered in any way.

The TOID is allocated sequentially when a feature is created by Ordnance Survey and is never reassigned to a different feature. One of the key principles of unique referencing is that the TOID will stay the same throughout the life of a feature. This gives the feature continuity within its life cycle and makes managing change of the product easier.

The product is designed to enable consumers of OpenData that is linked to the TOID to visualise that data in a spatial context. It bridges the gap between the disparate datasets of the OS MasterMap product family and enable the wider adoption of the TOID as a means of a spatial identifier, creating greater linking and sharing data with a spatial context.

This data is usable in a GIS application and can also be integrated into a spatial database.

Index

• Product details

• Data structure

• Product supply

Feature Content

The TOIDs included are drawn from the following feature tables from the following OS MasterMap products:

OS MasterMap Topography Layer

• TopographicArea

• TopographicLine

• TopographicPoint

OS MasterMap Sites Layer

• Site Extent

OS MasterMap Highways Networks – Roads

• RoadNode

• RoadLink

• PathLink

All features from each feature type above have been included in the OS Open TOID.

For each of the feature types included the following method of generalisation is used for the location:

• Point Features: the original location round to the nearest meter.

• Lines Features: the midpoint of the line rounded to the nearest meter.

• Polygons Features: use a point of inaccessibility algorithm to find a point that is guaranteed to be with in the polygon which is farthest from all edges. This location is then rounded to the nearest meter.

• Multi Polygon Features (Site Extent): use the same method as for polygon features on the largest of the polygons.

Coordinate Reference System (CRS)

The OS Open TOID and its associated geometry data layer uses the British National Grid (BNG) spatial reference system. BNG uses the OSGB36 (EPSG 27700) geodetic datum and a single Transverse Mercator projection for the whole of Great Britain. Positions on this projection are described using easting and northing coordinates in units of metres.

Introductory material on the BNG and Ordnance Datum Newlyn (ODN) along with the full definition of the BNG (OSGB36 National Grid) is available on the Ordnance Survey OS Net GPS site: https://www.ordnancesurvey.co.uk/gps/transformation/

A Guide to Coordinate Systems in Great Britain contains more details on working with coordinate systems.

A general introductory guide to BNG is provided at: https://getoutside.ordnancesurvey.co.uk/guides/beginners-guide-to-grid-references/

The OS Open TOID data carries five attributes which are all mandatory for each release. These can be used to identify and link affiliated information for a real-world object as well as plotting its real-world position. The TOID represents a range of feature types which related to an even wider range of real-world object types, examples range from buildings (including those without an address), roads, junctions, bridges, trees, fields and more.

OS Open TOID attributes

TOID

A unique identifier assigned to geospatial data by Ordnance Survey for their MasterMap products.

• Type: Varchar

• Size: 20

• Multiplicity: [1]

VERSION NUMBER

The date representing the version of the feature.

• Type: Integer

• Size: N/A

• Multiplicity: [0 ... 1)

VERSION_DATE

The date representing the date the feature was last updated.

• Type: Date Time

• Size: N/A

• Multiplicity: [1]

SOURCE PRODUCT

Attribute indicating which product a feature can be found in.

• Type: Varchar

• Size: 29

• Multiplicity: [1]

LOCATION X

A value in meters defining the x location according to the British National Grid.

• Type: Float

• Size: (precision, scale) - (10, 3)

• Multiplicity: [1]

LOCATION Y

A value in meters defining the y location according to the British National Grid.

• Type: Float

• Size: (precision, scale) - (10, 3)

• Multiplicity: [1]

GeoPackage structure

The GeoPackage data follows the same structure as demonstrated above, except for the inclusion of the following additional attribute:

id

A non-persistent integer which has been autogenerated as a function of OGC GeoPackage.

• Type: Integer

• Size: N/A

• Multiplicity: [1]

GeoPackage is also split between three different layers to allow for easier data interrogation; these layers are:

• os_mastermap_highways_network

• os_mastermap_sites_layer

• os_mastermap_topography_layer

Supply format

The OS Open TOIDs and Associated Geometry data will be provided in 100km tiles and distributed in two product formats using British National Grid (EPSG 27700) projection:

• Comma-Separated Value (CSV)

• GeoPackage (GPKG)

These formats allow the data to be easily integrated and ingested with either a database or a GIS application, respectively. Each tile will contain unique features that will not be shared across multiple tiles, as such there is not a 1:1 feature relationship between the OS Open TOID tiles and those in OSMM Topography Layer.

GeoPackage

GeoPackage is an open data format as is defined by the Open Geospatial Consortium (OGC). It is designed to be a lightweight format that contains both spatial (vector) and metadata tables in a single, ready-to-use file. Please note that older versions of GIS software may need updating before being able to display and interact with GeoPackage files.

Comma-Separated Value

CSVs are a simple file format used to store data, often in the form of a table or spreadsheet. These tables can be freely loaded into databases and programs allowing for the easy loading and updating of data holdings.

Supply update

OS Open TOID will be updated on a 6-weekly basis, in line with the OS MasterMap Topography Layer COU (Change Only Update) releases and will maintain consistency with OS MasterMap products.