The OS MasterMap Topography Layer is included in most UK Local Government accounts and is found in the 'OS Maps' collection. It is visible at large scales (zoomed in).

There is often a latency between when something changes in in real-life to when it appears on a map in your account.

How often is it updated?

The short answer is that updates are made to OS MasterMap every 6 weeks. However, this doesn't necessarily mean a new feature will be seen on the map 6 weeks later.

Let's look at the journey for that new information going from the ground to your screen:

  1. Something changes in the real-world. This could be a whole new housing estate, a new roundabout is installed or a building is converted into a semi-detached. At this point, Ordnance Survey do not know about it.
  2. Ordnance Survey conduct aerial and ground surveys to update their maps. These are pre-planned and usually cover a whole town in one go. They publicise what their plans are on this page.
  3. Once a new town has been captured by their aerial and ground surveyors, the information goes to their production team in Southampton. They then process the information to look for changes and then update their master copy of the database that makes up the MasterMap Topography Layer.
  4. Any changes to the map then go through a Quality Check process and then get made ready to be delivered to to their distributors, such as ourselves, in 6 weekly updates.
  5. When a new 6 weekly update is released by Ordnance Survey, we then take that new information and apply it to our own copy of the data. This can take a few days.
  6. Those updates are then published into our map feed and it'll be view-able by you in your account.

Reasons for delays

So even though there is a regular and constant stream of updates being made, you will not see them immediately. Delays include:

  • Ordnance Survey might not have your town or villages scheduled for an update anytime soon,
  • The update might be slight and hasn't been picked up by the surveyors,
  • The processing for changes takes some time, and/or,
  • The updates take a few days to apply to our servers.