Does anyone know if there’s a way to create boundary lines of postcodes - but not full postcodes?
To explain: If a postcode is M22 4DJ I would take off the last letter and want a map that showed the boundary of everything in M22 4D.
I’ve looked on Doogal but can’t find anything that fits this description. I can get a list of addresses but not an area boundary line. I would really appreciate any advice. Thanks!
I don’t think postcodes work like that with the last two letters. While the sector “M22 4” will be a coherent area, and units matching M22 4D* may be located near each other, I don’t think there is a hierarchical arrangement with the last two letters.
Postcodes are not areas with boundaries. They are labels applied to collections of delivery points (e.g. letterboxes). Those delivery points that have a common postcode do not necessarily all fall within one geographic area.
Postcodes do not exist where there is no delivery point. E.g. in the middle of a park, in the middle of a road, in the party wall between houses.
So there is no meaningful boundary.
Examples include E15 2 - the delivery points with E15 2xx postcodes fall into three distinct geographic areas, with other postcodes assigned to delivery points in between them (like E20 1.
If you want to see where the postcodes have been applied, you could try an overpass query along these lines:- overpass turbo
But the main problem you’ll find is that only a small proportion of the M22 postcodes have been added to OSM. You can view the percentages here: - Postcode Stats (M22) | Robert Whittaker's OpenStreetMap Stuff
I’ve just imported a few more postcodes in the M22 postcode district, but the counts won’t update until Robert’s stats next refresh.
There is a proposed scheme to generate them from UPRNs.