Post-office box

A post-office box or post office box (commonly referred to as a PO box or a postal box) is a uniquely addressable lockable box located on the premises of a post office station.

In many regions, particularly in Africa and the Middle East, there is no 'door to door' delivery of mail. For example, should one post mail to a street address in Namibia, it will be returned to sender as undeliverable. Consequently, renting a PO box has traditionally been the only way to receive mail in such countries, although some, like Jordan, Egypt and Lebanon, do have mail home delivery.

Generally, post office boxes are rented from the post office either by individuals or by businesses on a basis ranging from monthly to annual, and the cost of rent varies depending on the box size. Central business district (CBD) PO boxes are usually more expensive than rural PO boxes.

In the United States, the rental rate used to be uniform across the country. Now, however, a postal facility can be in any of seven fee groups by location; in addition, certain customers qualify for free box rental.