Policy statement – OS MasterMap Topographic Identifiers – TOIDs


A TOID is a unique identifier, consisting of the letters ‘osgb’ and followed by up to sixteen digits, associated with every feature in many of Ordnance Survey’s large scale products. The TOID is based upon the Digital National Framework concept and the principles that underpinned it. The TOID contains no attribution or information (for example coordinate position) about the feature, nor can information be derived from either the allocated number or the process by which it is allocated. The TOID will remain with the feature throughout the feature’s life and will not be reassigned to a new feature when the existing feature is deleted.

Permitted use

Ordnance Survey is committed to enabling the widest possible sharing and use of TOIDs. Hence, while Ordnance Survey is obliged under delegated authority to license and protect the Crown’s intellectual property rights, we allow the royalty-free use and sub-licensing of TOIDS (in each case limited to the TOID record and the associated TOID version number) in perpetuity by third parties who:

  • are (or were at the time the TOIDs were extracted) licensed to use the source Ordnance Survey data for their own Business Use, or;
  • have obtained TOIDS from the OS OpenData™ TOID look-up service.

In either case, they are free to:

  • sub-license the TOIDs to third parties free of any licensing restrictions; or
  • use the TOIDs to enhance their own products and/or services and sub-license such products and/or services to third parties free from any licensing restrictions, other than those that may apply in respect of such products and/or services.

The inclusion of Ordnance Survey data attributes (other than the TOID record or associated TOID version number), or datasets derived from Ordnance Survey data, will usually require licensing. Where any doubt exists users should contact Ordnance Survey.

Examples of how TOIDs can be used 

TOIDs can be shared with other users across different applications and systems. Data can be cross-referenced: for example, a user’s object or information may be linked to underlying geographic objects. This allows for: easier data association and greater accuracy, focusing on real–world objects; and easier information re-use. TOIDs facilitate correlation of data from different sources or datasets, for searching, analysis and querying of data, as an aid to information management, enhanced analysis and quicker decision making.

Collections of features may be aggregated into real-world objects such as schools, hospitals etc. by assigning a Feature Collection Identifier that references the composite TOIDs. 

Ordnance Survey, May 2014 

A ‘feature’ is any feature in a dataset representing a real world phenomenon. It may have a geometric property, including without limitation any line, point, polygon, symbol or text or it may have implied geometry by virtue of its relationship to other features. It has a spatial domain (attribute), a temporal domain, or a spatial/temporal domain as one of its attributes. Examples of features include almost everything that can be placed in time and space, including desks, buildings, cities, trees, forest stands, ecosystems, delivery vehicles, snow removal routes, oil wells, oil pipelines, oil spills and so on. Features are usually managed in groups as feature collections.