The postal system runs on post codes. It's a 5-8 letter code that usually identifies 1-20 ish addresses. You usually only need a door number and and a postcode

The postal system runs on post codes. It's a 5-8 letter code that usually identifies 1-20 ish addresses. You usually only need a door number and and a postcode to uniquely identify an address. There is free reverse look up as well.