the same as the P.O. Box address, and the last four digits (Zip + 4) are virtually always different. Except for a few of the largest post offices in the U.S., the 'Street Addressing' (not the P.O. Box address) nine digit Zip + 4 is the same for all boxes at a given location. Oceania Australia In Australia, wall-mounted PO boxes come in five sizes: small, medium, large, jumbo and A4. The different sizes boxes can be mixed almost completely arbitrarily on the wall. There is also an option for locked private bag which comes in two different sizes as well: small and large. PO boxes and private locked bags can be combined. New Zealand In New Zealand, customers have the option to select between two sizes of PO Boxes: small and large. There is also an option to hire a Private Bag similar to "locked bags" in other countries. The annual fee is paid annually in advance. See also Post box – used for outgoing mail Poste restante Private Mail Bag – delivered to recipient by contractor Virtual mailbox References External links Royal Mail's PO Box product and pricing web page Containers Postal infrastructure Postal systems