Detention

What it means

The same word is used for two different charges, billed by different parties under different rules, so it pays to know which one an invoice means.

The rest of this entry takes each meaning in turn. Who pays when a driver waits at a dock, and how to avoid it, is covered in who pays when a truck driver waits.

Detention in shipping: container per diem

On the ocean side, the FMC describes detention as a charge "for extended use of intermodal equipment."^[1] Where demurrage is tied to terminal land, detention is tied to the container itself: federal rules cover charges related to the use of marine terminal space or shipping containers, "including 'per diem' charges."^[2]

"Per diem" is the name truckers most often see. The Port Authority of New York and New Jersey's truckers guidebook defines it as a fee charged by the steamship line to a trucker for late return of equipment.^[7] Under the UIIA, which drayage carriers sign to interchange equipment, each provider's free time and per diem charges sit in its own addendum.^[8]

The FMC found the industry has no standard terminology, so its rule defines demurrage and detention broadly to include anything customarily called per diem. It limited the definition to shipping containers to exclude chassis, because depending on context per diem can refer to containers, chassis or both.^[6] Detention invoices from ocean carriers must follow the same FMC billing rule as demurrage, including the free time dates and charged dates.^[3] The FMC's reasonableness rule also says practices that charge detention when empty containers cannot be returned are likely to be found unreasonable, absent extenuating circumstances.^[5]

Carrier rules shape when the clock pauses. Hapag-Lloyd's U.S. guide, for example, starts detention free time the day after customs release when a container is held by customs outside the terminal, and excludes unplanned terminal and depot closures from detention charges.^[9]

Detention in trucking: driver waiting time

In trucking, detention is the charge a motor carrier bills when its truck and driver are held at a shipper's or receiver's facility past the free time agreed for loading or unloading. There is no single standard definition. The DOT Inspector General found that most of the industry measures detention as time at a facility beyond the limit in shipping contracts, often 2 hours, and noted that not all shipping contracts include detention pay clauses.^[10] FMCSA has said the industry, government and researchers have typically used dwell time over 2 hours to define it.^[11]

Each carrier publishes its own terms, and they differ:

• One truckload accessorial schedule charges detention on tractor time after a standard 2-hour window at pickup or delivery.^[12]
• Another carrier's rules tariff allows 60 minutes free, then charges $100 per hour, rounded to the nearest quarter hour, capped at $600 in 24 hours, with weekends and holidays included.^[13]

The OIG estimated that a 15-minute increase in average dwell time raises the expected crash rate by 6.2 percent, and that detention is associated with $1.1 billion to $1.3 billion a year in lost earnings for for-hire truckload drivers.^[10]

Why it matters

Mixing up the two meanings is a common billing mistake. Container detention stops only when the empty goes back to where the carrier says; truck detention stops when the truck is released. Unloading a container promptly protects the first, and a dock that is ready at the appointment time avoids the second.

Example

Illustrative only: an importer's drayage carrier picks up a 40-ft container on a Tuesday and drops it at the importer's warehouse. The carrier's tariff gives a set number of detention free days from gate-out. The warehouse cannot unload until the next week, so the empty goes back two days after those free days end, and the ocean carrier bills two days of detention (per diem). Separately, when the driver later returns for a live unload at a different site and waits three hours past the appointment under a contract with 2 free hours, the trucking company bills one hour of truck detention to its customer.

Demurrage vs. detention vs. per diem

• [Demurrage](term:demurrage). The full container is still on the terminal after free time. Billed by the terminal or ocean carrier.^[1]
• Detention. The container has left the terminal and is kept past its free days. Billed by the ocean carrier or NVOCC.^[1]
• Per diem. Usually another name for container detention, billed to the trucker for late equipment return.^[7] It can also cover chassis, which is why the FMC excluded chassis from its definition.^[6]

The demurrage vs. detention guide compares the two ocean clocks and how to dispute them.

Frequently asked questions