For anyone else who entered a US zip code and was confused by the ‘invalid zip code’ error: this is UK only.
Silly me, I entered an Austrian zip code out of principle. Did not expect it to work, though, of course.
Any plans to release the code? Would be nice to allow others to do something similar for their local pubs.
Yeah, they could reduce confusion by changing "the government" to "the UK government."
your first clue might have been that it does not say "zip code" in either the field label or the error message, it says "postcode".