April 2026

This release note provides information about the April 2026 release of OS MasterMap Sites Layer.

OS MasterMap Sites Layer provides a nationally consistent representation of polygon features that represent the area or extent of certain types of function or activity in Sites with the appropriate attribution. The product also includes Access Points to assist users in navigating into and out of the Sites (with references to the OS MasterMap Highways Network – Roads product).

Feature type counts

Feature Type	Previous Release Count (October 2025)	New Release Count (April 2026)
Functional Site (TOIDs)	49 197	49 347
Access Point (TOIDs)	148 592	148 600
Routing Point (TOIDs)	0	0

Note: Routing Points

Routing Points are no longer supplied from the October 2023 release onwards (see the 'Product Improvements' section below for full details).

Known data issues

Details of live and resolved data issues for OS MasterMap Sites Layer will be communicated on the OS MasterMap Sites Layer Known Data Issues page. This page will provide details of their impacts and updates on the expected time frame for their resolution.

Product improvements

To meet customer needs, Ordnance Survey has created a fully routable multi-modal network, and a key element of this is to provide more usable data about the access to destinations. To this end, we are now directly splitting our Road, Track and Path data where Access Link features connect to the network; this will allow customers to more easily route into Sites using OS network data.

Whereas previously some Access Points referenced Routing Points, all will now reference a Road Node from the OS MasterMap Highways Network – Roads product. Consequently, there is no requirement for Routing Point features, and these features are no longer supplied as part of the OS MasterMap Sites Layer product.

As a result, the Routing Point layer has not been supplied from the October 2023 publication onwards.

For customers that use Geography Markup Language (GML) format, there is no change to the schema, so product loading should be unaffected. However, please be aware that for customers using GeoPackage, no table for Routing Points is provided, and similarly for the vector tiles format, no layer is provided for Routing Points.

Next release

The next release of OS MasterMap Sites Layer is scheduled for October 2026.