What is the difference between port storage, demurrage and detention charges?

In their latest blog post, container repositioning platform Xchange provides a handy overview of the different charges ports can apply.

Port storage charges are levied by the port for containers that have not been moved out of the port within a specified free-time and affect yard space and port productivity. Usually, every port offers a certain free period between three and seven days to process import requirements and pick-up the container from the port. Costs are quite excessive in some countries if consignees are unable to take delivery of their equipment. May it be because of financial, documentary or contractual problems, as soon as consignees exceed the allowed free days the containers affect yard space, port productivity and congestion. To encourage importers, take care of cargo clearance issues and pick-up containers on time, ports charge storage fees.

Port storage charges are collected for full containers that are uncleared for import, full containers yet to be shipped for exports or empty containers within the port. Different terminals offer different free days, but usually, charges get circulated by the port and are valid for one year. It gets collected directly by the port or via the shipping line that sometimes even moves the container to a private depot to avoid storage charges for the customer.

However, it is slightly different from demurrage and detention charges. Shipping lines charge demurrage fees when clearance is delayed. Customers sometimes forget that port charges are levied by the port and just collected from the customer via the shipping line. It is possible that you have to pay both demurrage and port storage fees at the same time. However, there are countries like Japan, where both terms are used for the same charges.