The short version
- Demurrage is charged when a full container stays inside the terminal longer than the free time allows — typically because it has not been collected after discharge.
- Detention is charged when you keep the carrier's container outside the terminal too long — for example at your warehouse — until the empty is returned.
- Some carriers combine the two into one "D&D" free-time allowance. Terminals may also charge separate storage fees.
How free time works
Free time is the number of days you may use the container, or leave it at the terminal, before charges start. It is set in the carrier's tariff or in your contract, and it varies by carrier, port, direction (import or export) and container type — refrigerated containers usually get less. Most carriers count calendar days, so weekends and public holidays still count unless your contract says otherwise.
After free time, charges are applied per container, per day, and often rise in steps the longer the delay lasts. As a rough guide, demurrage and detention often run about $50–300 per container per day; your carrier's tariff is the real figure.
Why the charges build up
- Documents arrive late. If the original bill of lading has not reached the consignee, the carrier will not release the cargo. See when documents must travel by courier.
- Customs or inspection holds. Missing paperwork, a classification query or a physical inspection keeps the box in the terminal.
- Unpaid charges. Freight or local charges not settled before release.
- No truck or no dock space. Haulage capacity is tight, or the warehouse cannot receive the container yet.
- Arrival surprises. The vessel arrives earlier or later than planned, and pickup was booked around the wrong date.
Seven ways to avoid them
- Know the free time for every shipment, not just the usual lane. Write it next to the booking.
- Watch the real arrival date. Plan pickup around a live ETA rather than the schedule printed at booking.
- Get documents moving early. Courier original B/Ls as soon as they are issued, or agree a telex release or sea waybill with your supplier where your bank allows it.
- Pre-clear customs with your broker before the vessel berths.
- Book haulage in advance, especially before holidays and peak season.
- Return empties promptly — detention keeps running until the empty is back at the depot.
- Negotiate free time into your contract if your volumes justify it.
Work out your exposure
Use the demurrage & detention calculator to see what a delay would cost on your own numbers, and how much an early warning could save.