Coordinate reference systems

The Geography Markup Language (GML) and GeoPackage formats use 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.

Vector tiles format is supplied in Web Mercator projection (EPSG:3857). Web Mercator projection uses WGS84 geodetic datum to render the vector tiles.

The More than Maps platform has an in-depth guide to coordinate reference systems and mapping using the British National Grid here.