Port back-up (PBU) activities are an integral part of the overall port operation in Hong Kong. PBU uses are those port-related activities which are essential to the operation of port activities but do not need to be located within the confines of the port. These uses include container depots, container yards, container vehicle parks and container vehicle repair workshops.

Currently, there are about 380 hectares of land being used for PBU purposes and these PBU facilities are mainly located in the New Territories (e.g. Yuen Long, Lok Ma Chau).