In the US several federal institution have their own zipcodes, no box number required. So they might win the "shortest address" competition on this side of the

In the US several federal institution have their own zipcodes, no box number required. So they might win the "shortest address" competition on this side of the pond. For example: 20500 just goes straight to the Whitehouse, 20501 to the Vice President, 20511 to the Director of Intelligence, 20555 is the nuclear regulatory commission, etc.