Insights
Demurrage vs Detention Container Charges Explained
Few line items on a freight invoice cause as much frustration as demurrage and detention. The two terms are often used as if they mean the same thing, but they cover different stages of a container’s journey and are charged under different clocks. This guide explains demurrage vs detention for container shipments in plain language, so you can plan around them.
Demurrage and detention are two separate charges for two separate delays
Both charges exist because shipping lines and terminals own scarce, valuable assets: container yard space and the containers themselves. When a customer holds either one for longer than the contract allows, the line is compensated through a daily charge. The difference is where the container is when the delay happens.
Demurrage relates to the container sitting inside the port or terminal. If a loaded container is discharged from the vessel and is not collected before the free time expires, demurrage applies. On export, the same logic applies if a container is gated in at the terminal early and then waits beyond the allowed period before loading.
Detention relates to the container being outside the port or terminal. Once you have taken the container to your warehouse, site or customer, the carrier expects it back, normally empty, at a designated depot within the free period. Each day beyond that is charged as detention.
A useful way to remember it: demurrage is about the container occupying the terminal, detention is about the container occupying your premises or trucks. In practice a single shipment can attract both, one after the other, if cargo is collected late and the empty box is returned late.
Free time is the window that decides whether you pay anything
Free time is the number of days the carrier allows before charges begin. It is set in the carrier’s tariff or in your negotiated contract, and it is not the same everywhere. It can differ by port, by container type, by trade lane and by whether the container is standard, refrigerated or special equipment.
The clock usually starts at discharge or gate-in
For import demurrage, the clock normally starts when the container is discharged from the vessel. For detention, it normally starts when the container leaves the terminal or depot. For exports, the equivalent starting points are the pick-up of the empty and the gate-in of the loaded container.
Calendar days and working days are not the same
Some tariffs count every calendar day, including weekends and public holidays. Others count only working days. This single detail can change the outcome of a tight schedule, so confirm it in writing before you rely on the free period.
Free time is part of the commercial negotiation
Larger and regular shippers often negotiate longer combined free time or separate allowances for demurrage and detention. Smaller buyers can still ask the forwarder or line what is included and whether an extension fee schedule is available before booking.
The main causes of avoidable charges are paperwork, customs and trucking
Most overruns are not caused by a container being forgotten. They come from small failures along the chain. The most common are listed below.
- Original shipping documents arriving late, or the bill of lading not yet released, so the cargo cannot be collected.
- Customs inspection, a documentation query or a missing certificate holding the container in the terminal.
- Payment of freight or local charges outstanding, so the line will not issue the delivery order.
- No truck booked for collection, or no appointment slot at the terminal.
- The receiving site not ready to unload, or labour and equipment not available on the day.
- Empty containers returned late because the depot is full, closed or far from the delivery site.
Notice that almost none of these are about the sea voyage itself. They are coordination problems that can usually be solved before the vessel arrives.
Demurrage vs detention at a glance
The table below compares the two charges side by side so you can see which one applies to which situation.
| Point | Demurrage | Detention |
|---|---|---|
| Where the container is | Inside the port or terminal | Outside the port, with the customer or in transit |
| What triggers it | Not collecting a discharged container in time, or gating in too early on export | Not returning the empty container to the depot in time |
| Clock starts | Normally at discharge or gate-in | Normally when the container leaves the terminal or depot |
| Clock stops | When the container leaves the terminal or is loaded | When the empty container is returned to the designated depot |
| Who sets the rules | Carrier tariff or terminal rules | Carrier tariff or contract |
| Typical fix | Faster customs clearance and collection | Faster unloading and a confirmed return depot |
How to plan so free time is enough
Good planning is mostly about knowing the rules before the cargo moves and acting early once it does.
Ask for the free time terms before you book
Request the tariff for the specific port, container type and trade lane. Ask whether free days are calendar or working days, whether demurrage and detention are combined, and what happens at the daily rate after free time ends. Keep the answer in writing with your booking.
Prepare documents and customs early
Share draft documents with your forwarder or customs agent before the vessel sails, and check that your commercial invoice, packing list and certificates are consistent. Familiarity with transport and logistics planning helps you build in realistic time for each step.
Book trucks and receiving labour in advance
Line up the truck and the unloading team around the vessel’s expected arrival, not after it. If the site cannot unload immediately, consider arranging an agreed storage option rather than leaving the container to accumulate daily charges.
Confirm the return depot and return window
Detention disputes often start with an unclear return instruction. Get the exact depot, its opening hours and the return deadline, and keep proof of return such as an interchange receipt.
Raise problems early
If a delay is coming, tell the line or its agent before the free time ends. Requests for extension or waiver are far easier to support with evidence, such as a customs hold notice, than after the invoice arrives.
Ownership and leasing change your exposure
Demurrage and detention apply to carrier-owned containers moving under a bill of lading. If you buy a container outright, the box is yours, and the carrier’s detention clock no longer governs that unit in the same way. This is one of the reasons importers and storage operators who move cargo regularly compare ownership with other options. You can read about buying a container outright and the checks that matter on condition and specification.
Leasing is a middle route. A lease typically sets its own on-hire and off-hire terms, so the cost of keeping the unit longer is governed by the lease agreement rather than the carrier’s free time. The details vary by provider, so read the container leasing terms and return rules carefully, including where the unit must be returned and in what condition.
Whichever route you choose, check how documents such as the bill of lading, delivery order and any CSC plate or inspection records relate to the unit, because errors in these can hold a container at the terminal and start charges you did not plan for.
A practical verdict: control the controllable, and put the rest in writing
Demurrage and detention are not mysterious penalties. They are the price of holding someone else’s space or equipment for longer than agreed. You cannot remove every risk, because weather, congestion and inspections sit outside your control, but you can reduce most of the exposure by doing four things well.
- Read the free time terms for your specific port and container type before you book.
- Prepare documents and customs clearance before the vessel arrives.
- Arrange trucking, receiving labour and the empty return depot in advance.
- Tell the carrier early if a delay is coming, and keep written evidence.
If you are comparing options for a regular flow of containers, speak to a supplier who can explain buying, leasing and delivery together. You can see how to get in touch for a container quote and ask about the terms that matter for your route.
If regular shipments keep you paying detention, it is worth modelling ownership: compare the 40ft standard container specifications and the 20ft standard container specifications to see which unit volume fits your cycle.
Frequently Asked Questions
What is the difference between demurrage and detention?
Demurrage is charged when a loaded container stays inside the port or terminal beyond the agreed free time. Detention is charged when the container, once taken out of the port or depot, is not returned to the carrier within the agreed free time.
Who normally pays demurrage and detention?
The party named in the shipping contract and bill of lading is normally liable, which is often the consignee or the importer. Incoterms and your agreement with the forwarder decide how the cost is passed on, so check both before shipment.
Can free time be extended?
Often it can, but only if you ask the shipping line or its agent before the free period ends and agree terms in writing. Extensions are not automatic and are usually granted on a case-by-case basis.
Do weekends and public holidays count as free time?
That depends on the carrier's tariff and the port. Some count calendar days and others count working days, so read the tariff attached to your booking instead of assuming.
Does buying or leasing a container change these charges?
Yes. If you buy a container outright, the carrier's detention clock no longer applies to that unit, while a leased or carrier-owned container stays subject to return rules. This is one reason many regular shippers look at ownership.
Last reviewed: October 2026.
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