Detention
Also called: Container Detention · Detention Charge · Det
What is Detention in Shipping?
Detention is a charge you pay to the shipping line when you keep their container outside the port terminal for longer than the free time allowed. Once the container is delivered to you — at your warehouse, factory, or any other location — you have a fixed number of days to unpack it and return the empty container back to the shipping line's designated depot. If you take longer than that, detention charges start.
In simple terms: the container is the shipping line's property. They are lending it to you temporarily to move your cargo. The moment you exceed the agreed return deadline, you are charged for every extra day you hold on to it.
Think of it this way: Imagine you rent a car from a rental company. They give you the car for 5 days. On day 6 and beyond, extra charges kick in automatically. You are not being fined — you are simply paying for the extra time you used something that belongs to someone else. Detention works exactly the same way, except with a steel shipping container instead of a car.
How does detention work step by step?
Understanding detention is easier when you see the full journey of a container:
Step 1 — Container arrives at destination port. The shipping line notifies you (the consignee/importer) that your container has arrived and is ready for pickup.
Step 2 — Free time begins. From the moment the container leaves the terminal gate (or in some cases from the vessel arrival date, depending on the carrier's terms), a clock starts ticking. This is your free time — typically 3 to 7 days depending on the carrier and the port.
Step 3 — You receive the container. The container is trucked to your warehouse or facility. You unpack your cargo.
Step 4 — You return the empty container. Once unpacked, you arrange for the empty container to be picked up or dropped off at the carrier's nominated empty depot.
Step 5 — If you exceed free time. Every day beyond the free time window incurs a detention charge — billed by the shipping line, payable by you.
What is free time and how much do you get?
Free time is the number of days the shipping line gives you to use and return the container at no extra charge. It is included in your freight agreement and varies by carrier, port, and trade lane.
Typical free time at destination: 3 to 7 calendar days after the container leaves the terminal.
Some carriers offer extended free time on specific trade lanes or as part of service contracts. Others are strict about the standard window. Always check the free time allowance on your Bill of Lading or booking confirmation before your shipment arrives.
How much does detention cost?
Detention is charged per container per day. The rate typically increases the longer you hold the container — carriers use a tiered structure to incentivise faster returns.
A common tiered detention structure looks like this:
Days 1–3 beyond free time: $25 to $50 per container per day
Days 4–7 beyond free time: $50 to $100 per container per day
Day 8 onwards: $100 to $200+ per container per day
Example — 1 x 40ft container (FEU), free time is 5 days, container returned on day 13:
Days used beyond free time: 8 days
Days 1–3 at $50/day: $150
Days 4–7 at $100/day: $400
Day 8 at $150/day: $150
Total detention charge: $700
On a single container. If you are importing 10 containers and all of them are delayed by the same 8 days, that is $7,000 in detention charges on top of your regular freight costs.
What causes detention?
Detention is often not the importer's fault — but the charges still land on them. Common real-world causes include:
Customs clearance delays — If your documents are incomplete, your cargo is selected for examination, or customs processing is slow, your container sits at your end longer than expected.
Delayed customs documentation — Missing or incorrect invoices, packing lists, certificates of origin, or import permits hold up clearance and delay the return of the container.
Warehouse capacity issues — If your warehouse is full or your staff are unavailable to unpack quickly, the container sits longer than intended.
Port congestion — Sometimes the terminal itself is congested and containers cannot be picked up on time — even if you are ready. In these cases, carriers sometimes (but not always) waive detention.
Public holidays — A national holiday in the destination country can eat into your free time days, especially if free time is counted in calendar days rather than working days.
Slow trucking availability — Finding a truck to pick up and return an empty container is not always instant, especially during peak periods.
Detention vs. Demurrage — what is the difference?
This is one of the most confused pairs of terms in all of freight. They sound similar, they are often mentioned together, and both result in extra charges — but they cover completely different situations.
Demurrage — Charged when your container stays inside the port terminal for too long after the vessel arrives. Your cargo is sitting in the terminal and you have not picked it up yet. The terminal and shipping line charge you for occupying their terminal space.
Detention — Charged when your container has left the terminal and is outside with you, but you are taking too long to unpack and return the empty container to the carrier's depot.
The simplest way to remember it: Demurrage = container is still at the port. You have not picked it up. Detention = container has left the port. You have not returned it.
Both have their own free time windows and their own daily charge rates. It is entirely possible to incur both on the same shipment — if your container sits uncollected at the terminal for too long (demurrage) and then takes too long to be returned once you do collect it (detention).
Why does detention matter to you as an importer?
It adds up faster than you expect. Three or four days of delay across multiple containers can quietly generate thousands of dollars in charges that were never in your budget.
Customs delays are the biggest culprit. Importers often underestimate how long customs clearance takes — especially for first-time imports, regulated goods, or shipments that get selected for physical inspection. Factor this into your timeline.
Free time is shorter than it feels. Five calendar days sounds like plenty of time. But if your container arrives on a Thursday, day 5 is a Tuesday — and if you had a weekend plus a public holiday in between, you have had almost no working time at all.
It can delay your next order. If you are paying large detention bills on current containers, it affects cash flow and your ability to move quickly on restocking.
Forwarders can sometimes negotiate on your behalf. If detention was caused by factors outside your control — port congestion, a carrier error, customs system downtime — your freight forwarder may be able to get the charges waived or reduced. This is worth pursuing.
How to avoid or minimise detention charges
Prepare your customs documents before the vessel arrives. Have your commercial invoice, packing list, bill of lading, and any required import licences ready well in advance. The moment your vessel berths, customs clearance should begin immediately.
Know your free time before the shipment arrives. Check your Bill of Lading or ask your freight forwarder exactly how many free days you have and whether they are calendar days or working days.
Pre-arrange your trucking and warehouse. Do not start looking for a truck after the container arrives. Book in advance so pickup happens on day 1 or day 2 of free time.
Monitor vessel arrival closely. Vessels sometimes arrive early. If your container arrives 2 days ahead of schedule and your free time has already started, you could lose those days without realising it.
Negotiate extended free time upfront. For regular high-volume shipments, ask your carrier or forwarder for extended free time as part of your service agreement. Even 2–3 extra days can make a significant difference operationally.
Conclusion
Detention starts after you exceed the free time to return the empty container
Typical free time: 3 to 7 calendar days after container leaves the terminal
Charged per container per day — rates increase in tiers the longer you hold it
Detention is different from demurrage — demurrage is at the port, detention is outside the port
Customs delays are the most common cause of detention charges
Charges can be disputed and sometimes waived if the delay was caused by factors beyond your control
Frequently asked questions
1. Does free time start from vessel arrival or container pickup?
It depends on the carrier and the trade lane. Some carriers start free time from the vessel arrival date. Others start it from the date the container actually leaves the terminal gate. This distinction matters a lot — always confirm with your freight forwarder which rule your carrier applies.
2. Can detention charges be disputed?
Yes. If you believe detention was caused by port congestion, a carrier error, or circumstances genuinely outside your control, you can raise a dispute with the shipping line through your freight forwarder. Carriers do sometimes waive or reduce charges in legitimate cases, especially for long-term customers. Always keep records of pickup dates, customs clearance timestamps, and trucking receipts as evidence.
3. Is detention charged in calendar days or working days?
Most carriers charge in calendar days — weekends and public holidays count. This is why short free time windows can feel much tighter than they appear on paper. Some carriers offer working-day free time on specific trade lanes — check your contract terms.
4. What is combined free time?
Some carriers offer a single shared free time pool that covers both demurrage and detention together rather than separate windows for each. For example, 10 days combined free time across both demurrage and detention instead of 5 days each. This gives you more flexibility in how you use the time.
5. Who pays detention — the shipper or the consignee?
At destination, detention is almost always the responsibility of the consignee (the importer receiving the cargo). At origin, if a shipper holds an empty container too long before stuffing and returning it to the terminal for loading, that can also trigger detention — paid by the exporter.