Demurrage and Detention: How to Avoid Extra Container Charges

Demurrage and detention are two of the most common — and most avoidable — extra charges in container shipping. They catch importers out because they accrue quietly, per day, and can add up fast. Here is what they are and how to keep them off your invoice.

Two charges, often confused

They sound similar and are frequently lumped together, but they cover different things:

• Demurrage is charged when your full container sits at the port/terminal beyond the allowed free time, waiting to be picked up.
• Detention is charged when you keep the container outside the terminal — at your warehouse for unloading — beyond the allowed free time before returning the empty.

A simple way to remember it: demurrage is the box waiting inside the port; detention is the box being held outside it.

How free time works

Carriers grant a number of free days — often a handful — for each side: free time to collect the full container, and free time to return the empty. Beyond that, charges accrue per container, per day, usually on a rising scale that gets steeper the longer you go. On a multi-container shipment, those daily charges multiply quickly.

Why importers get caught out

• Customs delays — if clearance is not ready when the container lands, demurrage starts ticking.
• Slow unloading — if your warehouse cannot turn the container around quickly, detention builds.
• Empty return problems — congested depots or missed return appointments extend detention.
• Documentation issues — a B/L not released or paperwork queried can hold the box at the port.

How to avoid them

• Clear customs in advance. Have documents ready and clearance arranged before the vessel arrives, so the container can move the moment it lands.
• Plan unloading. Book labour and dock time so the container is emptied and returned within free time.
• Know your free days. Ask your forwarder how many you have on each side, and work back from there.
• Negotiate more free time. On regular or large shipments, extended free time can sometimes be arranged up front — far cheaper than paying daily charges.
• Return empties promptly and confirm depot appointments to avoid last-mile detention.

The bottom line

Demurrage and detention are almost always preventable with preparation: clear customs early, unload promptly, and know your free time. A good forwarder watches these clocks for you and flags a container at risk — but the fastest way to avoid the charges is to have everything ready before the box arrives.