Exchange of location point
Updated 9 August 2022
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This publication is available at https://www.gov.uk/government/publications/open-standards-for-government/exchange-of-location-point
Use the World Geodetic System 1984 (WGS84) and European Terrestrial Reference System 1989 (ETRS89) standards for consistent exchange of location point information in government.
1. Summary of the standards’ use for government
These standards are coordinate reference systems (CRS) that provide a way of defining and exchanging accurate 3-dimensional and 2-dimensional global location points.
WGS84 is a global CRS which enables the easy transfer of location point information with other countries. It is used in cartography, geodesy and navigation by GPS.
ETRS89 is a European CRS widely used to reference location points. The code for this standard in the European Petroleum Survey Group (EPSG) Registry is EPSG::4258. This registry contains information for developers implementing the standard.
By using the exchange of location point standards, the UK is keeping its commitment to implementing the EU INSPIRE Directive.
The government chooses standards using the open standards approval process and the Open Standards Board has final approval. Read more about the proposal for exchange of location points.
2. How these standards meet user needs
By using these standards, geographic location data is always clear and accurate. It is important to use the same standard coordinate mechanism to keep the location information the same across multiple applications.
These standards help you to:
- improve interoperability between systems
- reuse geographic data for multiple services
- improve the consistency of your location data
3. How to use these standards
To use these standards you must:
- define which CRS you’re using when publishing data
- use WGS84 for worldwide geographic location points
- use ETRS89 (EPSG::4258) for Europe
You can also combine these standards and/or add other CRS to meet your organisation’s requirements, for example, when you need greater accuracy for precision engineering decisions.
You must make sure these standards are interoperable with your IT network or system by:
- setting up your applications that use location data sets to refer to WGS84
- making sure your data sets covering European locations comply with INSPIRE by using ETRS89