Use of Ordnance Survey 1:25k data In Great Britain

I notice that field boundary data are available in OSM in Great Britain, which is very useful. However, most of the data are tagged with “source”=“OS 1:25k”. My understanding is that the OS 1:25k data are not available under an open licence, only a commercial licence. Please could someone explain how these data are made available in OpenStreemMap and whether they are usable outside of OpenStreetMap, with appropriate attribution of course.

Could you supply a link to an example of this?

So long as they’re over 50 years old, which the first series sheets made available by the National Library of Scotland are, then they’re out of copyright and can be used as a source.

There are even a small number of second series sheets that are now available.


An Overpass query:


(51.9, -2.5, 52.1, -2.24);

(51.9, -2.5, 52.1, -2.24);

out geom;

It’s actually very patchy. I’m wrong to say “most of the data” generally. Just in some locations, ones that happened to be the first I looked at.

Yes, that could be the source. The data don’t make that specific, just “OS 1:25k”. But a brief look at some examples doesn’t reveal any marked “OS 1:25k” that are clearly less than 50 years old.

In my experience most barrier=hedge and barrier=fence will be from imagery and survey rather than out of copyright 1:25k. Back in the early days of OSM out of copyright 1:25k was used more extensively because there wasn’t anything else, but 50 years is a long time in the life of a hedge.

If you link to where you are looking (just the URL at would do) we may be able to provide more information, and perhaps even comment on the mapping style of whoever first added those features.

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The area in the query I posted above in a reply above is the main one. I can no longer recall the other areas I tried.

Thanks to all who replied for your help and the explanations. I am happy using the data now.

I think the area information has got lost. Where was it, roughly?

That’s by a prolific Birmingham-based mapper. That far out of Birmingham I suspect that those edits will have been mostly imagery-based, perhaps helped by some previous on-the ground knowledge of the “lie of the land”.

I am surprised that many field boundaries are mapped from OS 1:25k imagery, it’s much easier from recent bing imagery and that provides more information such as if the field boundary is a fence or a hedge.

Also there has been a lot of destruction of field boundaries in the last 50 years making historic data less useful.

At one point, I believe the default source tag for the out-of-copyright 1:25k layers was just “OS 1:25k”, so it’s not at all surprising to see that in the dataset.

Yes, exactly this. The way at Way History: 48928732 | OpenStreetMap actually dates back to January 2010 and we didn’t have Bing imagery then.

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We also now have access to Environment Agency, Lidar Data (link). The second return(?) DSM is very useful since it removes most trees.

But, it appears to be slightly misaligned, so needs to be first aligned with OSM_UK Cadastral Layer.

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A bit of an aside, but if the Environment Agency LiDARS are all OK, what would it take to get them into the JOSM imagery list? the DTM looks very handy for some streams I know of with inconvenient trees blocking the view.

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An aside to an aside: how is JOSM connected to OpenStreetMap? The JOSM web site is short on things like “About Us”. What does JOSM add to OpenStreetMap’s available capabilities?

The OpenStreetMap website itself does not have the capability to edit data, it only offers an API which can be used by editor software to allow users to edit data. Popular editors include “ID” - the editor launched by default if you click on the edit tab - and “JOSM”, but there’s more, for desktop and mobile. Both ID and JOSM have their own and independent developer groups (even though the OSMF is a little more involved with ID development that it is with JOSM).

If your question is “what does JOSM add above what ID already does”, that’s hard to say in one paragraph but generally JOSM is perceived as the more powerful but less intuitive editor - you’ll have a steeper learning curve with JOSM but once you have mastered it you will be able to do more and quicker than with ID. JOSM has many advanced features that you might only rarely need but if you do they’re a god-send (for example, edit modes for making parallel lines or refining geometries). JOSM also has a lot of great plugins that can make your mapping life easier.