What are demurrage and detention?
Shipping lines allow a limited number of free days to use their containers. After that, they charge daily fees:
- Demurrage is charged while a full container stays inside the port terminal beyond the free time, for example because customs clearance isn’t finished or the truck isn’t booked.
- Detention is charged while the container is outside the terminal, at your warehouse or on the road, beyond the free time, until it is returned empty to the carrier’s depot.
Together they are often called D&D. Some carriers combine them into a single free-time allowance. Terminals may also charge separate port storage fees.
Core principle: The container is borrowed, not yours. Every day over the free time costs money, and the rates usually rise the longer it goes on.
Demurrage vs detention
| Demurrage | Detention | |
|---|---|---|
| Where the container is | Inside the port or terminal | Outside, at the warehouse or in transit |
| Clock starts | When the container is discharged from the vessel | When the container leaves the terminal |
| Clock stops | When the container is collected | When the empty container is returned |
| Typical cause | Customs delays, missing documents, no truck booked | Slow unloading, warehouse full, late return |
How to avoid the charges
Prepare customs before arrival
Have the commercial invoice, packing list and EORI with your broker before the vessel arrives.
Why it matters: Customs delays are the most common cause of demurrage.
Book the warehouse slot early
Agree the delivery date and unloading slot with your fulfilment centre as soon as the arrival date is known.
Watch out for: Peak season and floor-loaded containers take longer to unload, so book further ahead.
Negotiate free time
Ask your forwarder or carrier for extra free days in your contract, especially for regular shipments.
Why it matters: A few extra days often costs less than a single day of charges.
Check who pays
Your Incoterm and contract decide whether the supplier, forwarder or you pay D&D.
Watch out for: Charges caused by your own delays are usually yours, even if the freight was prepaid.
Example: A container arrives in Rotterdam with five free days. The commercial invoice is missing an HS code, and clearance takes four extra days. The container is collected on day nine, so the importer pays four days of demurrage. On day ten it reaches the warehouse and is unloaded and returned the same day, within its detention free time.
Frequently asked questions
What is the difference between demurrage and detention?
Demurrage is charged for keeping a full container in the terminal beyond the free time. Detention is charged for keeping the container outside the terminal beyond the free time.
How many free days do carriers give?
It varies by carrier, port and contract, often a few days for each. Regular shippers can negotiate more.
Who pays demurrage and detention?
It depends on the Incoterm and contract, but charges caused by the importer’s delays are usually paid by the importer.
Is port storage the same as demurrage?
No. Port storage is charged by the terminal operator, demurrage by the shipping line, although both can apply at the same time.
