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

Currently, there are about 414 hectares of land being used by PBU facilities which are mainly located in the New Territories (e.g. Yuen Long, Lok Ma Chau).