Detention refers to the charge incurred if a container is not returned to the shipping company within the previously agreed time. The so-called detention-free period begins when the container has been discharged from a ship.

As a rule, shipping companies have various empty container depots around the world. However, it may happen, for example, that there is no empty depot in the respective country and a container has to be returned to the seaport terminal after being unloaded at the consignee. The time required for this should be calculated in, as otherwise additional charges will be incurred.