A postcode and house number is all that's needed in theory in the UK, so something like `2 A12 1XY`. In reality that would be weird and people would add the street and town.

One issue also is that, even though the postcode pinpoints a small group of houses, it might happen to span two streets. It also gets complicated with flats and any number of other corner cases.

Addresses are complicated as anyone who has had to deal with them in code will testify.