Trucking dictionary

Demurrage

Demurrage: Demurrage is a charge for keeping cargo or equipment, usually a shipping container, at a port or terminal past its free time. In container shipping, demurrage generally covers time inside the terminal, while detention or per diem covers time a container or chassis is kept outside it. Ocean carriers and terminal operators bill these charges.

The rule on billing

The Federal Maritime Commission's rule at 46 CFR Part 541 sets the minimum information and procedures for demurrage and detention invoices issued by ocean common carriers, marine terminal operators and non-vessel-operating common carriers. It defines demurrage or detention as charges, including "per diem," related to the use of marine terminal space or shipping containers, not including freight charges.

Source: 46 CFR Part 541 (FMC), eCFR · checked 2026-10

In practice

For a drayage carrier, the clock matters at both ends: pick the container up before terminal free time ends, and return the empty before the container's free days run out.

One container's clock. EXAMPLE

Vessel discharged: Monday
Terminal free time: 4 days
Picked up: Friday: 1 day of demurrage
Container free days outside: 4 days
Empty returned: Day 6: 2 days of per diem
Who pays: Per the contract

EXAMPLE terms. Free time and rates vary by carrier and terminal.

Demurrage vs detention (two meanings)

In container shipping, demurrage is time at the terminal; detention or per diem is time the container is out.
In trucking, detention means pay for a truck kept waiting past free time at a shipper or receiver, which is a different thing entirely.

Read the contract or rate con to see which meaning applies.

Who pays demurrage?

The billed party named on the invoice, usually the shipper, consignee or whoever booked the move. A drayage carrier shouldn't absorb charges caused by terminal delays or late appointments without terms that say so. Get it in writing.

Can demurrage be disputed?

Yes. The FMC's billing rule sets what an invoice must include and the procedures billing parties must follow. Check the invoice against those requirements and the free time in your contract.

Steve Woods · Lead Dispatcher, TruckSprint

Steve Woods leads the TruckSprint dispatch desk and reviews every guide we publish. How we research and update guides.

Updated October 2026