UK open public data

Ordnance Survey, the British national mapping agency, has released open data at the beginning of this month. This is a 180 degree change for Britain. It used to have one of the most restrictive public data policies and hardly any official geo data was available. The new British open data policy is one of the most liberal policies worldwide and we can hope that other countries, in particular in Europe, will also understand the importance of unrestricted access to public data and adopt similar open policies.

The data is not only called ‘open’ it really is open. Unlike other ‘open data’ projects that use unopen share-alike licenses,  the OS OpenData is available under a so called ‘OS OpenData License‘, which is aligned and interoperable with the creative commons attribution license.

Of interest for GeoNames are several datasets:

  • 1.7 million postal codes (code-point)
  • 1:50’000 Gazetteer (260’000 toponyms)
  • admin boundaries

It will take some time and work till we can make optimal use of the data. The existing ‘outcode’ based postal codes have already been replaced with the new data. On the free server the postal code webservices (reverse and search) are now returning the full 1.6 million postalcodes. The dataset does not include postal codes for NIR, IM, GY and JE. For those regions we continue using the previous data.

The postal code dump directory now contains two files for GB, the default file with the outcodes and an additional file with the full postal codes. It is not yet clear whether we should continue with the outcodes or replace them entirely with the full codes. What do you think? Please comment your ideas and requirements below.

In order to use the admin boundaries we will have to clean up the existing admin divisions and align them with the Ordnance Survey divisions.

The gazetteer unfortunately only has a very high level ‘feature code’ and for the majority of the toponyms the feature code is missing entirely (X).

fcode | count
X | 128662 (all other features)
O | 41228 (other)
FM | 34723 (Farm)
W | 24425 (Water)
H | 14524 (Hill or mountain)
F | 8708 (Forest or wood)
A | 5252 (antiquity non-roman)
T | 1259 (town)
R | 237 (roman antiquity)
C | 62 (city)


8 thoughts on “UK open public data

  1. I was trying to use the geonames web service to query for the lat/long data corresponding to a specific post code. I could not use post codes such as LE4 XXX. Is the web service using the data provided by OS or am I missing something


  2. Please keep the Outcodes dump file available, it’s more manageable than the full file of 1.6 million addresses which a large amount of data to host & search through.

  3. thanks, jedev, for the feedback. We will keep two dump files. A small one with only the outcodes and the large one with the full codes.


  4. Hi, I have been using this on site above for some time without problem. In teh last couple of weeks the returned data has changed. I guess because of this change? I mailed support but they have not replied.
    My problem is i was using for UK town/county but that data is now missing for most UK postcodes. I see now contains Town/ county but includes terms such as boro.
    Frankly if this is the new format it is incorrect as postcode should return Wood Green.
    Help / advice please?

  5. Hi there, I tried to post my problem on the forum but the captcha does not work :-s

    Basically, I have imported both your Full UK Postcode dump and also imported the OS OpenData dump and converted the Eastings/Northings to latlon. I have compared the two data dumps and have found over 8000 post codes that are > 50 metres difference and up to 4 miles different. A quick check on google maps ascertains that the data from the OS Eastings and Northings converted using the library found here is the more accurate eg the postcode SA10 8BJ from your dump is as,-4.064941&sspn=16.921245,50.756836&ie=UTF8&ll=51.690436,-3.777924&spn=0.074703,0.198269&t=h&z=13&saddr=sa10+8bj&daddr=51.6747350109151%09-3.79656103370248 whereas the data from my conversion is as,-3.77799&sspn=0.074698,0.198269&ie=UTF8&t=h&z=15

    How Can I provide you the full dump of my conversions?

  6. B4PJS

    It is difficult to see the exact positions on these links. My current postgis installation returns for the latest os opendata file:
    select asText(transform(PointFromText(‘POINT(279195 204158)’, 27700), 4326));
    POINT(-3.75035057165856 51.7230866876135)

    Would this be more or less what you expect?

    The number of differences you found is so small that I assume the Eastings/Northings changed for those since I downloaded the file last year.


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