Demurrage and detention are not two names for the same charge. They are two clocks, running on two different sides of the terminal gate, and they are often owned by different parties. An importer who confuses them will negotiate the wrong free days and be surprised by the invoice that arrives three weeks after the cargo was delivered.
The short version: demurrage is charged while the container sits inside the port or terminal beyond its free period. Detention is charged while the container is outside the terminal, in your possession, beyond its free period. Demurrage is about occupying the terminal’s ground. Detention is about withholding the carrier’s box.
Where each clock starts and stops
On an import, the demurrage clock normally starts when the container is discharged from the vessel, or the day after, and stops when the container leaves the terminal gate. The detention clock then starts at that gate-out and stops when you return the empty container to the nominated empty yard or depot. On paper it is a clean handover. In practice, the two clocks overlap in the records more often than anyone would like, and the reconciliation is where money is found or lost.
On an export the sequence reverses. The detention clock usually starts when you pick up the empty container from the depot and stops when the loaded container gates in at the terminal. If that loaded box then sits in the terminal past the free period before the vessel sails, the demurrage or storage clock begins. Roll-overs are the common trigger: your box gates in for a Tuesday vessel, the vessel omits or the box is short-shipped, and it waits at the terminal for the next service. Whether the carrier waives that period depends entirely on why the roll happened and on how firmly you ask.
Note the asymmetry. On imports the exposure sits mostly with clearance and delivery speed. On exports it sits mostly with how early you take the empty and how well the gate-in aligns with the actual cut-off, not the published one. Our notes on ocean freight cover the cut-off sequence in more detail.
Who charges what
The carrier charges demurrage and detention on its own container. The terminal separately charges its own storage or ground rent for the space the box occupies. These are different invoices from different companies, and the free days do not have to match. It is entirely normal to have, say, seven free days of carrier demurrage and a shorter free period of terminal storage, so that terminal storage starts accruing while the carrier’s clock still shows free days remaining. Reading only the carrier’s tariff and assuming you are covered is a frequent and expensive mistake.
A third charge sometimes appears where a container is held under a customs examination or hold. The clocks generally keep running during an examination. Some carriers will consider a waiver for a hold that is demonstrably not the importer’s doing, but that is a commercial concession, not an entitlement, and you should not plan around it.
Usage varies, and you should check the wording
Terminology is not standardised across the industry. Some carriers publish a combined “demurrage and detention” or “merged D&D” tariff where a single clock runs from discharge to empty return, with no separate inside-outside split. Some markets use “port storage” for what another market calls demurrage. In parts of the United States the word “detention” is also used for truck driver waiting time, which is an entirely different charge. In common shipping law the word demurrage originally referred to vessel delay under a charterparty, and that older sense still turns up in contracts.
So do not argue from the word. Argue from the booking confirmation and the tariff page it points to. The only definitions that bind you are the ones in the documents you accepted. If you want the plain definitions written out, we keep them in the glossary.
Free days are negotiable before the booking and expensive after it
This is the single most useful thing to understand. Free days are a commercial term. They are set at the point of booking, alongside the rate, and at that moment they cost you almost nothing to ask for. Once the container is on the water, or worse, once the clock has run, you are asking for a credit note rather than a term, and the answer is usually a partial waiver at best.
Standard free days on Indian imports commonly sit in a low single-digit to roughly two-week band depending on carrier, trade lane, commodity and your volume with that carrier. Extended free time is routinely available on contract business and sometimes on spot bookings if you ask before you confirm. Rates typically step up in tiers, so day 15 costs more per day than day 8, and day 25 more again. The tiering is why a container that overruns badly can generate a charge that exceeds the freight.
Ask for free days in writing, ask for both the demurrage and detention figures separately, and ask what terminal storage free time applies at the discharge port. If the answer is vague, that vagueness is the risk.
Practical steps that actually reduce the charges
- Negotiate free days at booking, in writing, on both clocks. Include the empty return location, because a distant nominated depot quietly eats a day.
- Get documents to the broker before arrival, not after. Most avoidable demurrage is document lag, not customs. Filing early is the cheapest lever you have. See customs clearance.
- Confirm the original bill of lading or telex release is settled before the vessel berths. A container cannot be released against an unreleased B/L, and this delay is entirely self-inflicted.
- Know your actual arrival date, not the booking’s ETA. Vessel schedules move. Watch the box on tracking and plan transport from the berthing date.
- Line up transport and unloading labour in advance. If your yard cannot receive the container on the day it clears, you are paying detention for your own warehouse constraint. Pre-booked warehousing is often cheaper than detention days.
- Return the empty promptly and keep the interchange receipt. Disputed detention almost always comes down to whether you can prove the return date.
- Reconcile the invoice against the gate records. Errors happen in both directions. Check the discharge date, the gate-out, the gate-in of the empty, and which free-day count was applied.
When the charge is already running
Act on the same day, not at the end of the week. Ask the carrier for the current per-day rate and the tier steps, so you know what each further day costs. If the delay has a cause outside your control that is documented, submit a waiver request immediately with the evidence attached, not a narrative after the fact. Where the container itself is the problem rather than the cargo, ask about de-stuffing into a warehouse and returning the box, which stops the detention clock even if it costs handling. That trade is worth running the arithmetic on once the daily rate is in the higher tiers.
We should be honest about the limits here. Tariffs, free-day norms and waiver policies change, and they differ by carrier, by port and by contract. Nothing above should be treated as the current rule at any specific terminal. Check the tariff that applies to your booking, and if you want it checked for you, that is part of what we do at our Ahmedabad office.
Frequently asked questions
Is demurrage charged by the shipping line or the port?
Usually the shipping line, for its container occupying terminal ground beyond free time. The terminal separately charges its own storage or ground rent. Both can run at once, with different free periods, and both must be settled before the container is released.
Do demurrage and detention run at the same time?
Under the classic split, no. Demurrage runs while the box is inside the terminal, detention while it is outside. Some carriers publish a merged tariff with one continuous clock from discharge to empty return, so read the booking terms rather than assuming.
Can free days be increased after the container has shipped?
Rarely, and never on good terms. Free days are a commercial term set at booking. After shipment you are asking for a waiver, which is discretionary. Ask for the free days you need before you confirm the booking.
Does a customs examination stop the clock?
Generally not. The charges usually continue during an examination or hold. Some carriers will consider a waiver where the delay clearly was not caused by the importer, but this is a concession rather than a right, and policies vary.