Kinda meta, but this is the first time in a long time where I've put only the first half of my postcode in expecting it not to work and been surprised. Most of these "find your nearest XYZ" site require the full postcode which is just unnecessary unless you're looking for a fairly precise location. A full postcode can narrow your location down to an individual street, so its nice not to give too much away if you can.

For anyone not in the know, UK postcodes are made up of two parts: a general area (the outward code) and then a more specific one (the inward code.) Generally speaking a postcode + house number will be good enough to get a letter delivered to the right place, though the sorting office might not be too happy with you...

The format [0] is roughly: AB12 3CD, though the number of letters/numbers on the left side can vary a bit. As far as I know the second set of numbers is always 1 digit though, so that's how you can easily split the two sides of it to format it nicely. There's a couple of special ones that break the rules though.

[0] https://en.wikipedia.org/wiki/Postcodes_in_the_United_Kingdo...