Demurrage (Inside the Port)
Charged by the terminal or carrier when your full container sits at the port beyond its allotted "free time" (usually 3-5 days). This happens due to customs holds, lack of trucker availability, or missing documentation.
Detention (Outside the Port)
Charged by the ocean carrier when you take their empty container out of the port to unload at your warehouse, but fail to return the empty box within the free time. Fees compound daily and can easily exceed the value of the freight itself.