I like a pointless geographical challenge so at the start of the year I decided to try to visit all the postcode districts in London.
On 1st January I woke up in E3, then walked up the Olympic Park so that was E15 and E20 ticked off. By the end of the day I'd also visited E9, N1, N22, N11, W1, SW1, WC2, SE1 and EC1 - not deliberately but as part of my general perambulations. I've continued to tally where I've been ever since, and with my visit to UB11 this week I think I've visited all the postcode districts in London. This does however very much depend on how you define "postcode district" and "in London".
Even counting how many postcode districts there are is problematic. Let's start with the London postal district (as previously blogged here) and its eight postal districts: EC, WC, N, E, SE, SW, W, and NW
I've been to all of these. Admittedly they weren't all happenstance. I travelled around normally for the first three weeks, hitting about 50%, but then took a more careful look at a map and started thinking "oh, if I went there I could easily tick several more off". Pick your spot right and you can visit SE21, SE24, SE27 and SW2 in a few minutes. It only took another three weeks and I'd been to all 120.
But maybe I was missing a few. Officially several postcode districts are subdivided by letter because the number of addresses within them has skyrocketed since the system was introduced. E1 for example gave birth to E1W, a strip through Wapping, and SW1 is split into SW1A, SW1E, SW1H, SW1P, SW1V, SW1W, SW1X and SW1Y. Here's the full list.
Include these subdivisions and that's an extra 51 postcode districts, some extremely small, knocking the total up to 171. But when it came to visiting them I confess I thought "stuff that, life's too short". I'm happy enough to have visited WC2, I don't feel the need to have scooted individually round WC2A, WC2B, WC2E, WC2H, WC2N and WC2R. Where precisely is WC2H anyway?
And of course these 'compass point' postal districts don't cover the whole of Greater London. Several other postcode areas intrude into the outskirts, for example HA for Harrow, IG for Ilford and CR for Croydon. And here it gets trickier because postcodes and administrative boundaries rarely overlap so you have to work out which districts are genuinely in London and which aren't. Wikipedia reckons the outer London postcode areas are BR, CM, CR, DA, EN, HA, IG, SL, TN, KT, RM, SM, TW, UB and WD, but is that actually correct? This is where a map becomes essential.
Accurate maps of London postcode districts aren't easy to come by. Wikipedia has one (but you can't zoom in). Google Maps is clever because if you search for SW7 it draws a red line round SW7, although from experience the boundaries aren't very reliable. Various bespoke websites claim to depict postcode district maps, some approximately, some point by point. Hurrah then for london.gov.uk which does a stonking pdf map of London's postcode districts (plus a separate map for the complexities in the centre), although working out precisely which streets are in and which are out isn't always easy.
Take EN (for Enfield) for example. EN1 and EN2 are definitely wholly in Greater London. EN3, EN4 and EN5 are almost entirely in Greater London but small slivers spread outside. EN6, EN7, EN8 and EN9 are almost entirely outside Greater London but might potentially have slivers within. And EN10 and EN11 definitely aren't in Greater London (they're Broxbourne and Hoddesdon). The number of EN postcode districts in London is therefore at least five and might be as high as nine, but some proper research is needed to work out precisely how many.
I have attempted this research for all London's postcode areas and now present this surprisingly complicated table.
E1-E3 E5-E18 E20
UB1-UB8 UB10 UB11
IG1-IG6 IG8 IG11
CR4 CR7 CR8
KT1-KT3 KT5 KT9
KT7 KT17-KT19 KT22
TW6 TW13 TW14
TW17 TW18 TW20
194 postcode districts are wholly within Greater London. I've been to all of them this year. I've visited all the postcode districts contained inside London.
Another 20 postcode districts are mostly within Greater London. I've been to all of them this year too. I've visited all the postcode districts that are wholly or majority London.
15 postcode districts are marginally in Greater London. Only six of them have a significant London chunk, namely CR5, DA1, IG7, RM4, TN16 and UB9. The other nine I could have put into a category called 'Barely in London'. I've only been to six of these so far this year.
18 postcode districts might creep into Greater London. Boundaries suggest they might but they might not and the overlap might not contain any addresses. I need to do some more research to confirm (or exclude) these.
And 107 postcode districts aren't in Greater London. I've been to a few this year but for the purposes of my postcode challenge they're irrelevant.
To summarise, Greater London has at least 229 postcode districts (the first three columns) and maybe as many as 247 (the first four columns). My upcoming task is to deduce precisely how many there are and to visit all the rest of them.
And in case you hadn't worked out where this is going, I intend to visit these utterly tangential London postcode districts and then blog about them. Prepare to read about isolated farms, country lanes on the very edge of the capital, caravan parks and whatever else these borderline districts turn out to be. No rush, I'll visit them all eventually.