Many years ago I developed my first site that made use of UK Postcodes in order to locate train stations close to specific venues. At that time I investigated postcode databases, and what was available, I quickly realized that it was going to be very expensive to obtain a proper full postcode database, and eventually had to make do with a much more basic cut down version, which was generally fine for what I needed.

Ever since that first website I've messed with geolocation stuff, and in my current job I have worked with full postcode databases, and

various pay-per-lookup services. The amount of different postcode data varies quite a bit, from 'outcode' only data sets with just the first part of the postcode (which you can generally find for free), to full data sets with each and every address, postcode, and latitude/longitude data.

It has long been a desire for many web developers to be able to use full data sets, but for most of us it's impossible to cover the kind of costs involved in obtaining a proper license for this data.

Recently there have been several developments in the postcode data area. ErnestMarples.com was setup to provide a free look up service, but within weeks they were contacted by the lawyers acting for Royal Mail and told to take down the service.

Since then a lot of media coverage has occurred (The Guardian, The Register), and a petition has been set up.

Personally I think this kind of data should be free to use (certainly for non-commercial use). It allows us to people better websites, that provide content that is much more relevant to the visitor.

So get signing that petition people!

Current options for free postcode data includes the data set from Geonames.org and the leaked data set that's available from wikileaks.org (although using that might get you into trouble. ;).

Update: There's also a been a request made on the OPSI site for the Postcode data to be made avilable, you can vote here.