Opening property extents created from OS MasterMap Topography Layer

If you meet our simple publishing criteria, you don’t need to ask us permission to release your dataset – just simply let us know you're about to publish.

OS MasterMap Topography Layer shows the physical features on the ground at the time of survey, it never shows legal property boundaries, nor does it show ownership of physical features.

The vast majority of feedback received during engagement with the geospatial industry on this element of the Open MasterMap policy, stated that OS releasing a property extent dataset under OGL terms would cause confusion and be likely to lead to misuse of the data, for example, in the high value use case of conveyancing. This was due to the likelihood that it would be seen as authoritative, but would have no basis as such. The Geospatial Commission decided that OS should not release a property extents dataset under OGL, but deliver this element of the policy by removing OS restrictions on PSGA members publishing their authoritative data under these terms.

More information about the difference between OS data and HM Land Registry property data can be found on our property boundaries page.

Yes, in fact we would encourage you to do so.

Yes, in line with the OGL license, we simply ask that you acknowledge us with "Contains OS data © Crown Copyright and database right (year)"

OS OpenData support

Yes, we accept this is the inevitable outcome of the policy. All we ask is that you focus on the whole extent and make no attempt to attribute separate portions of your extents that either identify a section as being part of a building, or create a situation where a full detailed building footprint can be back-engineered from the data you release.