[Talk-GB] code-point_open accuracy

[Adrian]

The NSUL postcode overlay [1] [2] is often more useful than the Code-point Open postcodes. This is because the NSUL data contains postcodes for every delivery point.

[1] https://lists.openstreetmap.org/pipermail/talk-gb/2021-September/027693.html
[2] https://lists.openstreetmap.org/pipermail/talk-gb/2021-July/027254.html

Here is an example of exactly what Robert Whittaker describes [3] in relation to "Large User Postcodes." This building https://www.openstreetmap.org/way/248055393 is the Epsom branch of TrustFord (car dealer and garage). They give their postcode as KT19 9NW. That, it turns out, is the former postcode of a large user, which was withdrawn in 2015. The large user was presumably the previous occupier of the site. The NSUL overlay shows that the postcode for that location is KT19 9XX. (It's not a large user postcode because there are other locations with the same postcode.) And indeed if you look up the postcode for that business in the Royal Mail postcode finder, KT19 9XX is exactly what you get.

[3] https://lists.openstreetmap.org/pipermail/talk-gb/2023-January/029876.html