
Something I picked up from a tweet recently (can’t remember who from) was the effort to create a free database of UK postcode data via a site called Free The Postcode!. For those who don’t know, UK postcodes are essentially the same as zip codes in the US – Wikipedia tells me that we’ve had them in this country for 50 years now, since 1959.
note: in what is now the dim and distant past, I used to work for the Post Office’s IT division. I have no current association with the UK Post Office and what follows are entirely my own random thoughts on the subject.
The essential thrust of Free The Postcode is this: the Post Office currently charges people for access to their database beyond a certain number of queries per day. [I think they used to send updated copies of PAF (the Postal Address File) on CD to companies every month or so – presumably there’s now some online mechanism for distribution but I have no idea]. Much as Wikipedia has “freed” the world from having to buy hardback copies of Britannica, and OpenStreetmap is crowdsourcing a global map which is not bound by Ordnance Survey fees or Google control, wouldn’t it be great if we could do the same thing for postcode and address information in the UK?
Well… I guess. There are a few problems that I can see with the approach. The first is that only the Post Office can allocate, update and change postcodes in an area. In fact, every now and then they have done this over wide areas (Southampton’s SO codes were all changed or reorganised in the last ten or fifteen years I believe). The second is that in order to submit postcode information you need to know your GPS location (not so difficult these days with GPS being built into an increasing number of mobile devices) and the postcode you are currently in. Now, unless you are at home or at the office, this is potentially a bit more tricky – so actually building this free database could take a very long time. Also, in order to draw accurate boundaries, you will need a lot more than a single reading from each postcode area.
In the interests of experimentation, and my doubts notwithstanding, I thought I’d give this a try. There’s a free iPhone application called iFreeThePostcode which works out where you are and then allows you to submit your location and the postcode online (by the way, there are also Android applications, or a web form).

A couple of interesting points here. Firstly, I found it fascinating to see how long it took my phone to get a location lock with better than 50m accuracy – it started off at over 1000m and gradually narrowed itself down (jumping up over 300m on a reasonably regular basis). The other thing is that I had to fill in my email address in order to go through a validation process – they send you an email with a “confirm that you submitted this” link, presumably to avoid spammers. That’s fine, but as many of the comments in the iTunes store reviews say – I’m handing over personal data here, and there’s no statement as to how that might be used. To be fair, the current content of the database is available as public domain, but that doesn’t mean that the people gathering the data don’t have other purposes.
Besides that, there are some interesting legal discussions on the associated wiki page, and no overall stated privacy policy for the project.
If you’re interested, by all means give the FreeThePostcode project a look. I can’t quite say whether or not I’m in favour of the idea – frankly, I think this is a tricky problem to solve through crowdsourcing.
Update: the source code of the iFreeThePostcode app is available.
Interesting – I shall post my gps coordinates later, however my postcode is rather interesting. The even numbers have one postcode, and the odd numbers another. I wish someone could explain how/why that happened…
Well that’s it, isn’t it – apparently strange things like that can only really be described by the authority that owns / defines the data. Not sure it’s easy to encapsulate in a free crowdsourced effort like this.
Actually, one of the more basic things I find frustrating about access to postcode information, is that I want a simple postcode district map in jpg format. Sounds simple, but you try googling that and see how much people want to charge you for something that has been around for many years and should be free. If you aren’t aware of what a district map is, it takes you to the first 1 or 2 letters, e.g. GU = Guildford