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Demurrage and detention: the two clocks that start when the vessel arrives
The freight is paid, the ship has docked — and new charges begin anyway, because the carrier’s container is now on a clock. Demurrage and detention are the two most misunderstood lines on an arrival invoice. They are also the easiest to avoid.
The two clocks, in one table
| Term | What it measures | Where the container is |
|---|---|---|
| Demurrage | Import: from container discharge to when the full container leaves the terminal. Export: the mirror image — an empty picked up too early or a full gated in too late. | The container is inside the port or terminal. |
| Detention | Import: from gate-out to the empty container’s return to the depot. Export: from empty pick-up to full gate-in. | The container is out in the world, on your truck or your site. |
| Free time | The days the carrier allows for all of the above before any charge runs. | Varies by carrier, port and tariff — your arrival notice states yours. |
Carriers publish per-port tariffs with scaling daily rates — one major carrier’s published explainer shows import free time commonly around a week with per-day charges rising the longer the box sits — but the exact figures differ by carrier, port and trade. The number that applies to your shipment is on the arrival notice: read the free-time line first, before anything else on the page.
Why these charges exist
A container is the carrier’s equipment, and its business model needs the box back. Every day a container sits — at the terminal or in your yard — is a day it earns nothing and someone else cannot use it. Free time is the negotiated grace period for the unglamorous reality of unloading, clearing and returning a box; the charges after it are designed to be annoying enough to keep cargo moving. That is also the defence against them: keep the box moving.
Where first-time importers actually lose money
- Documents not ready. The shipment arrives, but the customs paperwork — invoice, packing list, transport document, registrations — takes another week to assemble. The demurrage clock ran the whole time.
- Duty or registration surprises. An importer number, tax registration or broker arrangement that was never set up; clearing “later” is a per-day price.
- No unloading plan. The container is released, then sits at a site with no forklift while a solution is found — that is detention, at daily rates, plus the truck waiting.
- The forgotten empty. Unpacked, but the empty box sits on site for days before anyone arranges its return. Pure detention, pure waste.
The defence: three dates, one habit
When the vessel sails you receive the pre-alert with the arrival notice. From that moment, three dates matter: the arrival date (free time starts), the last free day (printed on the notice), and your clearance readiness (documents, duty funds, delivery plan). Line them up and demurrage never starts. The habit that makes it work: have your import registration and broker sorted before the first shipment, not during the free week — our duty & landed-cost guide lists what each country typically asks for.
One more nuance worth knowing: customs exams can extend the time a container spends in the terminal. Where that happens, keep the exam paperwork — many terminals and carriers handle the extension differently, and a forwarder who notices the clock early is exactly who you want holding it.
Want the arrival week to be boring?
Tell us the destination early — we confirm the free time, the clearance path and the delivery plan before the vessel sails.