Demurrage and detention at UK ports: free time and how to avoid charges

Three charges, one clock

When a container comes off the ship, the shipping line (the carrier) gives you a set number of free days to clear it through customs, collect it and send the empty box back. After that, daily charges start. Three words get used for these charges, and carriers do not always use them in the same way.

• Demurrage: a charge for leaving a full container at the port or terminal beyond the free days. It runs from the day the box is discharged from the ship until it leaves the terminal.
• Detention: a charge for keeping the carrier's container outside the terminal for too long. It runs while the box is with you or your haulier, until the empty is returned.
• Terminal storage: a charge for the space the container takes up at the port. In the two carrier tariffs we checked, storage reaches you through the carrier, either inside the demurrage charge or invoiced under that name.

The names vary. Maersk's UK import tariff (opens in a new tab) charges "combined detention" for the whole time from discharge until the empty is back, and invoices port storage as "demurrage". Hapag-Lloyd's UK import tariff (opens in a new tab) charges import demurrage while the box is at the port, with storage included, then separate detention once it has been picked up. Read the terms for your own booking rather than assuming they match another carrier's.

How free days are counted

Three rules catch people out.

• The day the container comes off the ship usually counts. Maersk's storage and combined detention both start on, and include, the day of discharge. Hapag-Lloyd's tariff says sea demurrage starts on the day the unit is discharged from the vessel.
• Free time is counted in calendar days, so weekends count. Hapag-Lloyd's tariff also states that bank holidays are included.
• The clock stops only at the right place. For storage, that is when the full container is gated out of the terminal. For detention, it is when the empty is gated back in at the terminal or depot the carrier has named.

Rates also rise the longer you go over. Both tariffs charge in bands, with the daily rate stepping up after the first chargeable days, so each extra week tends to cost more than the one before.

An example using a published tariff

This is an illustration only. It uses Maersk's UK import tariff in force from 1 August 2026 for a 40ft dry container at Felixstowe or London Gateway. Under that tariff, storage is free for days 1 to 5, then £51 a day for days 6 to 10. Combined detention is free for days 1 to 7, then £80 a day for days 8 to 12 and £115 a day for days 13 to 17. Your own booking may have different terms, especially on a spot or contract rate.

1. The ship discharges on a Friday. That Friday is day 1, and Saturday and Sunday are days 2 and 3.
2. Storage free time ends on Tuesday, day 5.
3. The customs entry and a haulage slot are not ready until Wednesday, day 6, so one day of storage is charged: £51.
4. The container is delivered, but unloading waits until the following Monday. The empty is gated back in at the depot on Tuesday, day 12.
5. Combined detention is charged for days 8 to 12, five days at £80: £400.

In this example, a few days of slippage adds £451 to one container, and one more day would have moved detention into the £115 band. You can run your own dates through our demurrage calculator.

What eats into your free days

• Weekends and bank holidays. A ship that discharges late in the week, or just before a bank holiday, leaves fewer working days to act.
• Late paperwork. If the customs entry or the carrier's release is not ready when the ship arrives, the box sits while the days count down. Import jargon, explained covers the documents involved.
• Customs and other checks. A container selected for examination is held until the check is done. Neither tariff we read says the clock pauses for checks, so ask your carrier before assuming it does.
• Collection slots. Hauliers need a booked slot to collect a container. At London Gateway, the vehicle booking system (opens in a new tab) is mandatory for every collection, and under the terminal's banded tariff in 2026, peak and short-notice bookings cost more.
• Slow unloading or a late empty return, which runs up detention after the box has left the port.
• Several containers arriving in the same week, so your warehouse cannot take them all at once.

What can give you more time

Free time is not always fixed. Maersk's UK page says free time is as agreed between the carrier and the customer, and it points to its spot booking product as one way to extend free time at destination. In practice:

• Ask your forwarder what free time comes with the rate, in writing, before you accept the quote.
• If you regularly need longer, for example because your warehouse is small or your goods are slow to unload, ask for extra free days to be built into the rate before you ship.
• Check whether free time is quoted as separate demurrage and detention days or as one combined allowance. A combined allowance lets you decide how to split the days between the port and your warehouse.

Practical ways to avoid the charges

1. Know your free days, and the date they run out, before the ship arrives.
2. Get customs and release sorted early. Send your customs agent the invoice and packing list as soon as the supplier issues them, and pay any carrier charges in good time so the container is released.
3. Book haulage early, especially in busy weeks and before bank holidays.
4. Plan the unload. Have people and space ready on delivery day, and agree when the haulier will collect the empty.
5. Return the empty to the depot the carrier names, and keep a record of the gate-in time.
6. Stagger arrivals if you can, so containers do not land in the same week.

If charges do arrive

Ask for a day-by-day breakdown. Check the discharge date, the gate-out date and the empty return date against your own records, and count the days yourself, starting with the discharge day. Then check the rate against the tariff that applied to your booking. Tariffs change: Maersk's page, for example, says free time and charges follow the price calculation date at origin, and it shows the previous schedule alongside the current one.

If you think a delay was caused by the port or the carrier rather than by you, raise it with your forwarder straight away, with dates. What can go wrong, and what we do about it covers delays more broadly.

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