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A few extra days can turn an otherwise straightforward container shipment into an expensive one. The vessel arrives, but the import documents are not ready; later, the container leaves the terminal, but unloading and empty return take longer than planned. These delays can give rise to two different charges: demurrage and detention.
In brief: in many ocean-freight tariffs, demurrage applies when a carrier’s container remains at the port or terminal beyond its free time. Detention applies when the container has left the terminal but is returned late. Terminal storage may be a separate charge. Always check the applicable carrier and terminal terms for the exact definitions, start dates and free days.
The carrier’s container is still at the port after terminal free time has expired.
The container leaves the terminal, is unloaded and must be returned to the designated location.
Returning the carrier’s empty container takes longer than the allowance in the tariff.
What does free time cover?
Free time is the period allowed under the carrier’s terms before the relevant demurrage or detention charge begins. There is no universal number of free days. The allowance depends on the carrier, location, equipment, import or export move, service and booking agreement. Do not assume the seven days granted on a previous shipment will apply to the next one.
Some quotations specify separate allowances for time inside and outside the terminal. Others offer combined demurrage and detention. If a combined allowance is ten days and the container spends seven of them at the terminal, only three days of that same allowance remain for collection, unloading and empty return. The exact start event, calendar-day rules and treatment of holidays belong in the tariff review.
Demurrage, detention and storage: what is the difference?
| Charge | Typical situation | Question to ask |
|---|---|---|
| Demurrage | The carrier’s container remains at the port or terminal beyond the applicable free time. | What is preventing the container from leaving the terminal? |
| Detention | The container has been collected, but is not returned to the designated location on time. | When will unloading and empty return be completed? |
| Storage | Terminal, port or depot space is occupied beyond the period allowed under its own terms. | Will the terminal bill storage separately? |
More than one charge can arise on the same shipment. Seeing storage and demurrage on separate invoices does not, by itself, mean the same item was billed twice. Terminology and charging boundaries also vary by market and tariff; the applicable contract and published terms take precedence over any general guide.
Can one container incur both charges?
Yes. Imagine an import booking with five free days at the terminal and, separately, three days after gate-out to unload and return the empty container. Missing documents hold the box at the terminal beyond the first allowance, potentially creating demurrage. It is then collected, but the warehouse is not ready to unload it, so empty return exceeds the second allowance and detention may follow.
That example assumes separate allowances. Under combined free time, there are not two independent clocks: each day spent at the terminal uses part of the total time available to return the empty container.
How are the charges calculated?
Daily rates vary with the carrier, port, 20-foot or 40-foot container, dry or refrigerated equipment and the number of chargeable days. Many tariffs increase the daily amount in stages. Here is an illustrative calculation only: days 1–5 are free, days 6–10 cost $50 per day, and day 11 onward costs $100 per day. If the container remains until the end of day 13, under that assumed counting method:
These are not actual tariff rates, and another tariff may count days differently. The later rate bands and the number of containers can make a small delay costly: an extra $80 per container per day becomes $800 a day across ten containers.
Where do avoidable delays usually begin?
Demurrage risk often starts before arrival: a bill of lading, invoice or permit is missing; the consignee, package count, weight or container number does not match; customs inspection takes longer than expected; or clearance funds are not ready. Arrival just before a holiday may consume some of the allowance. Recheck the vessel’s estimated time of arrival (ETA) close to discharge, because schedules can move.
Detention risk begins after collection. The warehouse, labour or forklift may not be ready; a truck or return slot has not been arranged; or nobody has confirmed where the empty box must be delivered. Getting the container out of port quickly solves only half the problem. Plan the return trip before gate-out.
What should you confirm before booking and arrival?
Get the inside- and outside-terminal free time in writing. Confirm whether it is separate or combined, when the clock starts, the stepped rates, holiday rules and the nominated empty-return location. If clearance or unloading may take longer, ask whether more free time is available.
Check the commercial invoice, packing list, bill of lading, permits and payment arrangements with the customs broker. Monitor the ETA and reserve the truck, warehouse space and unloading equipment.
Record the empty-return deadline, follow the unloading plan and obtain proof that the container was accepted at the designated return point.
Suppose one freight offer is $1,700 with little free time and another is $1,800 with a longer allowance. If your cargo requires permits or testing, the cheaper freight rate may not produce the lower landed cost. Container terms are part of the real price comparison.
What if free time is almost over?
First, confirm the exact expiry date and the next tariff band with the carrier or forwarder. If the container is still in port, identify the immediate obstacle: documents, permit, customs, payment or trucking. Prioritise actions against the cost of another day. If it has already left, concentrate on unloading and returning the empty container.
These charges are not limited to imports. On an export move, collecting an empty container too early, having cargo unready for stuffing, or bringing the loaded container to the terminal late can also generate equipment-use charges under the applicable terms.
When asking NIKCO.LOG about ocean freight, include free time and the demurrage and detention terms in your quote request. The ocean rate alone does not show the full exposure to delay.
The general definitions in this guide were checked against Maersk’s demurrage and detention terms and CMA CGM’s general terms. Confirm dates, holidays, rates and charge names against the tariff and contract for your own shipment.
Plan the next shipment