Hi Tom,

I was following the advice of the wiki, which advises that the "addr:suburb" be used as the catch-all tag for places more local than the postal town: https://wiki.openstreetmap.org/wiki/Addresses_in_the_United_Kingdom

"The addr:suburb tag should be used in cases where the address includes a sub area to the major location/postal town. This sub area could be a hamlet, village, town or an area of within a larger settlement."