johnstone93 funny answer...but in reality if an item has a return address on the reverse and it cannot be delivered it is returned to the displayed address...Should there not be a return address then it is sent to a dedicated centre where they can legally open an iten to trace it's origin...in which case it is returned under cover stating that it has not been delivered because-????????-.....A company like a bank has so many return addresses it would be impossible to get the right one.....50 houses may have the same Post-Code so I would be like returning it to 'Just Someone' in the street