You clear customs, your trucker is booked, and then the terminal calls: there is a balance due before your cargo can leave. The invoice lists "demurrage" and "detention" as separate line items, and together they have quietly added up to more than you paid for the shipment.
Both charges exist because carriers and terminals need their equipment and their space back. But they measure two different things, run on two different clocks, and are billed by two different parties.
What Is Demurrage?
Demurrage is charged by the terminal (or the carrier, depending on the lane) when your container sits in the port yard beyond the free period. The terminal needs the slot. Other cargo is waiting. Every day your box sits uncollected, you pay.
Typical free time at major Chinese origin ports runs three to five days. At destination ports in the US and Europe it can be as short as two days for busy terminals during peak season.
Once free time expires, demurrage rates usually start at $75–$150 per container per day and escalate in tiers — often doubling after day five or seven.
What Is Detention?
Detention is charged by the carrier when you hold their container outside the terminal longer than the agreed free period. Once the trucker picks up the box, the detention clock starts. You have a set number of days — often three to five at destination — to unload and return the empty.
Detention fees are similar in magnitude to demurrage: $100–$200 per day per box at many carriers, with escalating tiers.
Why the Confusion?
Both charges involve containers sitting idle, so importers often use the words interchangeably. The critical difference:
- Demurrage: box inside the terminal, terminal billing you.
- Detention: box outside the terminal in your yard or at the stuffing location, carrier billing you.
Some carriers bundle both under a single "D&D" line item. Others separate them. Always read the charge description.
How Free Time Actually Works
Free time is negotiated — or in many cases simply set by the carrier's tariff — and it can vary by:
- Lane: transpacific lanes often have different schedules than Asia-Europe.
- Volume: if you ship regularly, you may be able to negotiate extended free time.
- Container type: reefer containers typically get shorter free time because demand is higher.
Free time on the import side usually starts the moment the vessel discharges — not when you pick up the container. If there is a customs hold, the clock may still be running.
Common Reasons Charges Build Up
- Customs examinations or holds that add days before you can pick up
- Documentation errors causing clearance delays
- Trucking appointments being unavailable (especially at congested ports)
- Warehouse receiving hours that limit how quickly the empty can be returned
- Simply not knowing the free time window had started
How to Avoid Demurrage and Detention Charges
Track your vessel and estimate arrival early. If you know the ship is landing on Thursday, line up your customs broker, trucker, and warehouse well in advance. Use the freight tracking features on ChinaLogisticHub to stay ahead of ETA changes.
Know your free time before booking. Ask for the carrier's free time schedule at destination in writing. It should be in your booking confirmation or the bill of lading terms.
Build buffer into your operations. If free time is four days and a customs exam typically takes two, that leaves two days. One truck delay and you are in demurrage territory.
Negotiate extended free time on high-volume lanes. If you import regularly, a freight forwarder with volume leverage can often secure an extra two or three days — which pays for itself after one avoided charge.
Use a customs broker who communicates proactively. Delays you know about let you adjust. Delays you discover only when the invoice arrives do not.
Can You Dispute Demurrage or Detention Charges?
Sometimes. If the container was not available for pickup during your free time — because of a vessel delay, a terminal systems outage, or a carrier-caused hold — you may have grounds to dispute. Keep records: terminal availability confirmations, email timestamps, customs hold documentation.
If the delay was on your side, disputing is harder, but carriers do sometimes waive first-time charges if you have a clean record and a respectful conversation.
The Bigger Picture
Demurrage and detention are symptoms of a tight supply chain. The real fix is visibility: knowing where your cargo is, when it arrives, and having your logistics chain ready to move the moment it does.
If you want to get a clearer picture of your total landed cost — including the risk of these charges — our landed cost calculator lets you model the full cost of a shipment before it even books.
For a deeper look at the other line items that show up on freight invoices, see hidden import costs: the full checklist and ocean freight rates explained.