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 our 'Guide to Coordinate Systems in Great Britain' for more information on CRSs.
This 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.
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:
TopographicArea
TopographicLine
TopographicPoint
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.
TOIDs are unique and persistent identifiers, assigned by OS, for real-world features that have a physical presence in the world around you, such as a building or a road. A TOID consists of the letters ‘osgb’ and either 13 or 16 digits between 0 and 9. The TOID is allocated sequentially when a feature is created by Ordnance Survey and is never reassigned to a different feature.
For the TOID to be fully effective, it is essential that the OS-appointed TOID reference is not altered in any way.
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.
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.
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.
This overview includes the following sections:
On this page you'll find product supply information for OS Open TOID, including available formats, the supply mechanism, coverage and currency.
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.
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 (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 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.
OS Open TOID is supplied as a free online download and is available without registration from the OS Data Hub.
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.
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 and will maintain consistency with the OS MasterMap products).