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Compatibility of the OS OpenData Licence with ODbL


The current view taken by Ordnance Survey and OSM's Licensing Working Group is that the OS OpenData Licence is not compatible with the Open Database Licence (ODbL) used by OSM. Therefore contributors may not make use any OS OpenData Licensed material for OSM contributions, unless separate permission from the Rights Holder(s) has been obtained.

The only such permission that I am aware of is described in this email and covers the OS OpenData products listed here with the exception of CodePoint Open.

In February 2015, Ordnance Survey announced that they were switching from their own OS OpenData Licence to the Open Government Licence for their OS OpenData Products. The OS OpenData pages don't seem to have been updated yet to confirm the new licence, and it's not clear what will happen to third-party data (e.g. that such as Public Rights of Way data coming from PSMA exemptions) currently being released under the OS OpenData Licence. But we can be hopeful that the problematic OS OpenData Licence will soon be a thing of the past.


OpenStreetMap (OSM) makes its mapping data available under the Open Database Licence (ODbL) with the content licenced under the Database Contents Licence (DbCL). Thus any third-party data contributed to OSM must be available under a licence that can allow onward distribution under these licences.

The standard Open Government License 2.0 is explicitly forward compatible with the Open Data Commons Attribution License (ODC-By), which in turn is forward compatible with the ODbL. Thus material licenced under the OGL can be contributed to OpenStreetMap.

Ordnance Survey (OS) and various other public sector bodies make certain dataset available for re-use under the OS OpenData License. These datasets would be very useful for helping improve OpenStreetMap. The OS OpenData Licence is similar to the Open Government License 2.0 (OGL), but contains some additional conditions.

In the absence of any special agreement with the Rights Holder(s), the key question to be answered is "Can I take OS OpenData licenced data, and release it under the ODbL+DbCL (with appropriate attribution)?"

Legal Analysis

The OS OpenData license clearly states that any sub-licenses must include an attribution requirement, and must also enforce a similar attribution requirement on any further downstream usage. Arguably, this is not guaranteed by the ODbL, since attribution in produced works needs only point back to the source database, and not list all individual sources that went into creating that database.

Ordnance Survey's View

Ordnance Survey has been rather inconsistent in their statements regarding whether or not OS OpenData Licensed information can be subsequently released under the ODbL. Previously some people have been told that it can be.

However, the most recent communication I have had from the Office of Public Sector Information after their consultation with OS casts doubt on this. The email I received is as follows:

Date: Mon, 11 Mar 2013 12:32:30 +0000
From: XXXX
To: 'Robert Whittaker'
Subject: OS OpenData Licence Compatibility [UNCLASSIFIED]

Dear Mr Whittaker,

We have had a response from our colleagues at Ordnance Survey, following their consultation with OS legal representatives. Ordnance Survey has confirmed that the OS OpenData Licence obligations on copyright acknowledgement continue - notwithstanding the licensee's entry into the ODC-By or the ODbL. Therefore, the OS Open Data copyright acknowledgments apply in addition to any acknowledgments required by the ODC-By or the ODbL (e.g. under clauses 4.2 and 4.3 of the ODC-By).

It the opinion of Ordnance Survey that this requirement for an acknowledgement means that the OS OpenData licence is not forward compatible with the ODC-By and ODbL. Both the ODC-By and ODbL are very clear that: "Sometimes the contents of a database, or the database itself, can be covered by other rights not addressed here (such as private contracts, trademark over the name, or privacy rights / data protection rights over information in the contents), and so you are advised that you may have to consult other documents or clear other rights before doing activities not covered by this License ".

Clause 2.4 of the ODC-By states: "2.4 Relationship to Contents in the Database. The individual items of the Contents contained in this Database may be covered by other rights, including copyright, patent, data protection, privacy, or personality rights, and this License does not cover any rights (other than Database Rights or in contract) in individual Contents contained in the Database. For example, if used on a Database of images (the Contents), this License would not apply to copyright over individual images, which could have their own separate licenses, or one single license covering all of the rights over the images" There are similar terms in the ODbL so neither licence precludes the fact that other rights (and terms) may therefore apply in addition to those set out in the ODC-By and ODbL.

It should be highlighted that the OS OpenData Licence terms relate not just to Ordnance Survey's copyright, but also to the copyright of Royal Mail and the Office for National Statistics in relation to Code-Point Open. It should also be noted that the inclusion of an acknowledgement of copyright helps Ordnance Survey to track how OS OpenData is being re-used and hence its value, which is potentially useful information for the open data community in general.

I hope this explanation from Ordnance Survey is helpful to you.

With regards


Information Policy Adviser

The explanation seems rather confusing to me. The question I really wanted answered was "Can I take OS OpenData licensed data, and release it under the ODbL+DbCL (with appropriate attribution)?" If I'm reading the reply correctly, they're saying "no", because OS's attribution requirements are in addition to those required by ODbL, and they can only be achieved under ODbL by protecting the contents with a separate license. Presumably OSM can't offer that additional protection in data that gets released under its standard licence. If this is correct, then I guess that means that OS are saying that we can't use OS OpenData licenced material in OSM, without specific permission from the copyright holder(s).

Whatever the detail though, the statement that "the OS OpenData licence is not forward compatible with the ODC-By and ODbL" seems clear-cut enough.

OSM Licence Working Group's View

Michael Collinson summarises LWG's position in two emails to the talk-gb mailing list. The first email provides background and discussion, the second email provides the following summary:

LWG view on use of data in OSM under OS OpenData License:

Yes: OS OpenData product except CodePoint

No: CodePoint (a Royal Mail response to Chris Hill needs further investigation)

You need to formally ask: Any other dataset published under the OS OpenData License by other organisations, such as English Heritage, (or by OS if any).

What datasets are covered by the OS OpenData Licence

The initial datasets released by Ordnance Survey as their "OS OpenData" set of products are all licenced under the OS OpenData Licence. These include:

With the exception of Code-Point Open, OSM has obtained a separate permission to use these datasets in OSM. However, this permission does not help anyone else who may want to make use of these datasets in projects that use the ODbL or ODC-By licenses.

In addition to the OS OpenData products, the Public Sector Mapping Agreement (PSMA) allows public sector bodies to apply to OS to release certain classes of geographic data generated in part by reference to OS products under the OS OpenData Licence. (Without this exemption, OS would claim rights to the data, because of the use of OS products in its generation.) Such datasets include:

Possible resolutions to allow data under the OS OpenData Licence to be used in OSM

In decreasing order of preference the following would allow OS OpenData Licenced material to be used in OSM:

  1. OS simply adopt the standard Open Government License 2.0, which explicitly says that it is forward-compatible with Open Data Commons Attribution License. This in turn implies compatibility with the ODbL, and hence the data can be contributed to OSM.
  2. OS modify their OS OpenData Licence to make it clear that the additional attribution requirements do not over-ride the compatibility statement in the included text from the OGL.
  3. OS make a formal statement to the effect that the additional attribution requirements in the OS OpenData Licence do not over-ride the compatibility statement in the included text from the OGL.
  4. OS give special permission to OSM to make use of any of their IP which is licenced under the OS OpenData Licence.

Option 1 is preferable, since it reduces the number of different licences that consumers of Open Data have to deal with, and eliminates any uncertainty in the licencing terms. Option 2 is also fine, provided the amendments are clear. Ideally, these options would be applied to all datasets currently available under the OS OpenData Licence. But a possible compromise would be to allow OS to continue the status quo (or one of the other options below) for its own data, but ensure that third-parties releasing data under the PSMA use a more compatible licence.

Option 3 is less desirable, since it relies on users having to check a second document. Since the document would only represent OS's interpretation, it would be unclear whether it would bind third parties who license their IP under the OS OpenData License. (This is a particular issue for datasets released by third-parties under the PSMA provisions, where IP will be owned jointly by OS and the Third Party.) Option 4 is less desirable still. It suffers from the same issues as option 3, and comes with the additional drawback that it would only apply to OSM. Thus it would deny other potential users of the benefits of using the data under less restrictive licences.

Ongoing Developments

It would appear from the ODUG Minutes of 11 June 2013 that Open Data User Group is currently looking in to the problems associated with downstream use of OS OpenData Licenced data. We might be hopeful of some progress soon.

In June 2014, I had the opportunity to meet with some officials from the Department for Business Innovation and Skills. They were keen to hear my views, but I'm not sure I managed to explain the subtlties of the problem well enough for them to fully appreciate it. I left them with a printout of this page.

In November 2014, I responded to The National Archives request for feedback on OS during their IFTS verification of Ordnance Survey thus:

I understand from​/information-management​/keeping-touch​/re-users-licensees-rss-feed/ that you are currently conducting a an Information Fair Trader Scheme (IFTS) verification of Ordnance Survey. I would like to make the following points regarding the OS OpenData Licence, which they use for their own OS OpenData products, and force third-parties to use under the PSMA exemptions scheme.

I believe that the current OS OpenData Licence fails "Maximisation" and "Simplicity" principles of the IFTS.

The OS OpenData Licence (OS-ODL) at​/docs​/licences​/os-opendata-licence.pdf is based upon the standard Open Government Licence (OGL), but includes some additional terms, which add additional attribution obligations.

It is my belief (and this has been confirmed previously by Ordnance Survey) that these additional terms break the licence's forward compatibility with the "Open Data Commons Attribution License" (ODC-By) -- i.e. data used under the OS-ODL cannot be added to a project that wants to release its combined data under the ODC-By licence. This compatibility is explicitly guaranteed in the OGL, but is broken by OS's extra terms. This breaks the "Maximisation" principle.

Moreover, even if the additional terms were found to be ok, the lack of an explicit statement in the licence that it remains forward compatible with ODC-By will make life more difficult than it needs to be for users -- thus breaking the "Simplicity" principle. (The compatibility statement in the OGL only applies to the OGL itself, and so can't be taken to automatically apply to any amended licence.) Users should be able to determine quickly, and without needing to take legal advice, whether the OS OpenData Licence is compatible with other popular licences.

Finally, I would note that in the OS OpenData agreement between OS and DCLG (now BIS) at​/request​/199705​/response​/498165​/attach/4​/OS%20Opendata​%20Agreement%20Redacted.pdf, there is an explicit requirement for OS's licence to be "interoperable with the licence on". The only reasonable interpretation of that clause would be that the OS OpenData Licence is forward-compatible (in the manner described above) with the OGL that is used by Since the OGL is explicitly forward compatible with ODC-By, then the OS OpenData Licence would need to be too.

The minimum action required to rectify this situation, is for the OS OpenData Licence to be amended to include an explicit statement of forward compatibility with the OGL and ODC-By licences. This would address the "Maximisation" principle. But better still, and to better comply with the "Simplicity" principle, OS should just use the latest version of the OGL unamended. There is no need for the added burden on users of having to deal with a separate licence here. Note that it is still possible to specify specific attribution clauses under the unmodified OGL.

On 17th February 2015, Ordance Survey announced that they would be changing from their own OS OpenData Licence to instead use the Open Government Licence v3.0 for their OS OpenData products (blog post containing the announcement). The relevant licensing pages have yet to be changed, and it's unclear exactly what will happen to OS-derived geodata released under the PSMA exemption. But this is certainly excellent news. I'm not sure exactly what prompted / forced this change, but kudos to OS and (probably) National Archives for listening to the issues.