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.
The distinction
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.
How free time is counted
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:
- Are the days calendar or working days? Weekends and public holidays consume calendar free time and can eat half of it.
- When does the clock start? Usually on discharge or on availability notification, not on the day you were told the vessel arrived.
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.
What actually causes the charges
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.
How to stop the clock
- Prepare the entry before arrival, not after. The broker needs documents days ahead, not on discharge day.
- Book the drayage in advance and give the trucker the release requirements.
- Confirm the free days at quote stage and negotiate more where clearance is known to be slow.
- Have a warehouse slot booked for the day you plan to collect. See our Miami warehousing if you need staging near the port.
- Return the empty promptly and keep the interchange receipt, because disputed returns are common.
Disputing a charge
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.
FAQ
What is the difference between demurrage and detention?
Demurrage is for time inside the terminal; detention is for time with the carrier's container outside the terminal.
When does free time start?
Usually on discharge or availability, depending on the carrier's tariff. Confirm which applies before the vessel arrives.
Are weekends counted?
If free time is expressed in calendar days, yes. Working day free time is more generous and less common.
Who pays demurrage, the shipper or the consignee?
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.
Can demurrage be waived?
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.