Detention

Detention is the charge a carrier bills you for keeping its container outside the terminal — at your warehouse or yard — beyond the free time you were granted to load or unload and return it empty. The clock runs from the moment you take the box off the terminal until you hand the empty back, so it is one of the easiest accessorial costs to control if you plan the turnaround.

When detention applies

Detention starts once you have picked up the container and free time has expired, and you still have the box in your possession. Typical causes:

• Slow unloading at your warehouse because of a labour or dock shortage
• Holding a loaded export container while you finish stuffing it
• Delays returning the empty to the depot (no slot, no haulier, depot closed)
• Container used as temporary storage on site

The charge accrues per container, per day, and rates climb after the first few days. Reefer and special-equipment boxes attract higher daily rates than a standard dry container type.

Detention vs demurrage

The two charges are constantly confused because both penalise you for going over free time. The difference is location — is the container inside the terminal or outside it.

	Detention	Demurrage
Where the box is	Outside the terminal (your yard/warehouse)	Inside the terminal / port
What it penalises	Holding the carrier's equipment too long	Occupying terminal space too long
Trigger	Free time after pickup expires	Free time before pickup expires
Charged	Per container, per day	Per container, per day
Who bills it	The shipping line / carrier	The shipping line / carrier

In short: demurrage runs while the container sits in the port; detention runs once you have taken it away. Move too slowly on collection and you pay demurrage; move too slowly on return and you pay detention. The full breakdown is in demurrage vs detention.

How to avoid detention

• Confirm the free-time days in your booking before the container ships
• Book your unloading slot and the empty return at the same time
• Pre-clear customs so the box is not held by paperwork — see customs clearance
• Have a haulier and depot slot ready for the empty leg before you unload
• For repeat lanes, negotiate longer free time into the rate

Detention is avoidable cost, not a fixed cost. Tightening the turnaround on every box adds up across a year of volume.

UMERA lets you put the loaded leg and the empty return out to multiple carriers as one RFQ and compare quotes — including free-time terms — before you commit, so detention exposure is priced in from the start.

FAQ

What is detention in shipping?

Detention is a charge the carrier applies for keeping its container outside the terminal, at your premises, beyond the agreed free time. It is billed per container, per day, until you return the empty.

How is detention different from demurrage?

Detention applies when you hold the container outside the terminal; demurrage applies while the container is still inside the terminal or port. Both are per-container, per-day charges from the carrier.

How can I avoid detention charges?

Plan the empty return before you unload, book your dock slot and depot slot together, pre-clear customs, and negotiate longer free time on regular lanes.

Who pays detention charges?

The party named on the bill of lading or the booking — usually the importer or the consignee handling the unloading — pays detention, though a freight forwarder may invoice it on the carrier's behalf.