Demurrage and detention are the two charges most likely to turn a well priced shipment into an expensive one, and the two most often confused. They are different clocks, run by different parties, for different reasons.
Demurrage is charged for cargo that stays inside the terminal beyond the agreed free time. You are paying the terminal, through the carrier, for occupying yard space.
Detention is charged for the carrier's container being kept outside the terminal beyond the free time. You are paying for the equipment, not the space.
On an import, demurrage runs from discharge until you collect the container; detention runs from collection until you return the empty. On an export, the sequence reverses: detention runs while you have the empty for loading, and demurrage applies if the loaded box sits at the terminal past its window.
| Charge | Where the box is | Whose asset |
|---|---|---|
| Demurrage | Inside the terminal | Terminal space |
| Detention | Outside the terminal | Carrier's container |
| Storage | Warehouse or CFS | Warehouse operator |
Some ports and carriers merge the two into a combined charge, sometimes called merged demurrage and detention. Read the tariff rather than the label.
Free time is agreed at booking, expressed in days, and it varies by lane and by contract. Two details decide whether you use it well:
Rates escalate by tier. The first days are moderate, the next tier costs more, and the third can be several times the first. Charges compound per container per day, so a delay on a five container shipment escalates quickly.
Customs holds, incomplete documentation, missing ISF, and manifest descriptions that trigger examination. Missing the release because the invoice was unpaid. No truck booked. A warehouse with no dock slot. Chassis shortages at the destination port. Almost none of these are freight problems, which is why they are rarely anticipated in a freight budget.
Filing discipline prevents most of them. Our notes on ISF filing requirements and AMS filing cover the two filings that most often hold a container.
Charges are disputable when the delay was caused by the carrier or terminal: no appointment availability, equipment not released, gate closures. Document everything with timestamps, keep the appointment attempts, and raise the dispute quickly. Waiting until the invoice ages weakens the case.
Demurrage is for time inside the terminal; detention is for time with the carrier's container outside the terminal.
Usually on discharge or availability, depending on the carrier's tariff. Confirm which applies before the vessel arrives.
If free time is expressed in calendar days, yes. Working day free time is more generous and less common.
Whoever controls the leg where the delay occurs, as decided by the Incoterm and the contract of carriage. On imports it usually lands on the consignee.
Sometimes, when the cause was outside your control and documented. Speed and evidence decide the outcome.
Tight clearance windows on your lane? Ask us to structure the free time before the booking is placed.