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Detention
Definition
Detention is a charge for holding equipment beyond the free time allowed: in ocean shipping, for keeping the carrier's container out too long (often called per diem); in trucking, for keeping a truck and driver waiting at a shipper or receiver.
In simple English
Somebody kept equipment longer than the free time allowed. For a container it is the carrier's box; for a truck it is the truck and driver waiting at a dock.
What it means
The same word is used for two different charges, so it pays to know which one an invoice means.
| Container detention (per diem) | Truck detention | |
|---|---|---|
| What is held | The ocean carrier's container, outside the terminal | The truck, trailer and driver, at a shipper or receiver |
| Clock usually starts | When the equipment free days after pickup run out | After the free waiting time in the contract, often 2 hours |
| Clock usually stops | When the empty is returned | When loading or unloading is finished and the truck is released |
| Billed by | Ocean carrier or NVOCC, under its tariff or contract | The motor carrier, under its rates or contract |
On the ocean side, the FMC describes detention as a charge "for extended use of intermodal equipment."[1] Federal billing rules treat it together with demurrage, "including 'per diem' charges."[2]
On the trucking side there is no single standard definition. The DOT Inspector General found that most of the industry measures detention as time at a shipper or receiver "beyond the limit established in shipping contracts--often 2 hours," and noted that not all contracts include detention pay.[3] FMCSA has said the industry, government and researchers have typically used dwell time over 2 hours to define it.[4] Carriers publish their own terms: one truckload schedule charges detention after 2 free hours,[5] another after 60 minutes.[6]
Why it matters
Mixing up the two is a common billing mistake. Container detention stops only when the empty goes back; truck detention stops when the truck is released. Unloading a container promptly stops the first, and a dock that is ready at the appointment time avoids the second.
Related
Related terms
- DemurrageDemurrage is a charge for a loaded container that stays at the marine terminal after its free time runs out.Glossary
- Free TimeFree time is the number of days a container can stay at the terminal, or stay out with the importer, before...Glossary
- LayoverA layover is a charge for a driver and truck held overnight or for a long unplanned stop because a load could...Glossary
- Accessorial ChargeAn accessorial charge is a fee added to the base freight rate for extra services or events, such as...Glossary
- ChassisA chassis is a wheeled trailer frame built to carry a shipping container over the road; the container is...Glossary
Related questions
- Who Pays When a Truck Driver Waits at a Shipper or Receiver?Usually the carrier bills detention to the party it contracted with, under the rate confirmation, contract or...Answer
- Live Unload vs. Drop Trailer: What Is the Difference?In a live unload the driver and truck wait at the dock while the trailer is unloaded. In a drop, the driver...Answer
- How Long Can a Container Stay at the Port?There is no single limit; three clocks apply. Commercially, a container can sit at the terminal for the free...Answer
- What Happens After a Container Arrives at Port Newark?After the vessel discharges, the container has to be released by both Customs and the ocean carrier before...Answer
Related freight problems
Related guides
Sources
- Federal Maritime Commission, “Detention and Demurrage,” Government guidance. Accessed September 2026.
- Legal Information Institute, Cornell Law School, “46 CFR § 541.3, Definitions (demurrage and detention),” Federal regulation. Accessed September 2026.
- U.S. Department of Transportation, Office of Inspector General, “Estimates Show Commercial Driver Detention Increases Crash Risks and Costs, but Current Data Limit Further Analysis (Report ST2018019),” Government report. Published January 31, 2018. Accessed September 30, 2026.
- Federal Motor Carrier Safety Administration, Federal Register, “Agency Information Collection Activities; Impact of Driver Detention Time on Safety and Operations (88 FR 58060),” Federal Register notice. Published August 24, 2023. Accessed September 30, 2026.
- Union Pacific, “Accessorial Charges and Payment Terms (truckload),” Carrier accessorial schedule. Accessed September 30, 2026.
- Heartland Express, “SRG "A": Rules and Accessorial Charges,” Carrier rules tariff. Accessed September 30, 2026.
General operational information, not legal, customs or regulatory advice. Rules and rates change; confirm current requirements with the agency, carrier or contract that governs your shipment.