Demurrage vs Per Diem — and How to Avoid Both

Demurrage and per diem are the two fees importers dread most, partly because they are so easy to mix up. Both are penalties for holding something too long. The difference is what you're holding and where it is. Get that straight and you can plan your drayage to avoid both.

What is demurrage?

Demurrage is charged by the marine terminal when your container sits inside the terminal past its allotted free time. When a vessel is unloaded, the terminal gives you a set number of free days to pick the container up. Once that window — your "last free day" — passes and the box is still on the terminal, demurrage starts accruing, usually per container per day, and often on a rising scale the longer it stays.

In short: demurrage is the fee for leaving the box in the terminal too long.

What is per diem (detention)?

Per diem — frequently called detention — is charged by the steamship line when you hold their equipment outside the terminal past the free time. Once you pull the container out for delivery, another clock starts: you have a set number of free days to unload it and return the empty container (and sometimes the chassis) to the terminal or depot. Keep the equipment beyond that window and per diem accrues per day.

In short: per diem is the fee for keeping the box (and gear) out too long.

Demurrage is the box waiting in the terminal. Per diem is the box waiting out at your yard. Same idea — a free-time clock — on opposite sides of the gate.

Why they add up so fast

These charges are daily and per container, so a handful of boxes stuck over a weekend can turn into a serious bill. Several things push importers into demurrage and per diem at once:

Short free-time windows. Free days are shrinking at many ports, leaving little margin for error.
Terminal congestion. Appointment scarcity can make it hard to pull a box before the last free day.
Chassis shortages. No chassis means no pickup, even when you're ready.
Slow unloading. A container that lingers at your dock delays the empty return and triggers per diem.
Weekend and holiday gaps. Clocks often keep running even when your operation is closed.

How to avoid demurrage

Pull before the last free day. Give your carrier the terminal, container number and last free day early so they can secure an appointment in time.
Pre-pull when it's tight. Have the carrier pull the container off the terminal early and hold it at a yard — a small pre-pull and storage fee usually beats escalating demurrage.
Clear customs early. A container on a customs hold can't be released; stay ahead of documentation.
Use a local carrier. A drayage team based near the terminal can grab appointments and turn moves faster.

How to avoid per diem

Unload fast — or transload. If your dock can't unload quickly, move the cargo off the ocean container into trucks. Transloading frees the container to go back immediately, stopping the per diem clock.
Use drop-and-pick. The carrier drops the loaded container and returns for it, so you unload on your schedule while the driver stays productive. Compare the trade-offs in drop-and-pick vs live unload.
Book appointments early. Return appointments can be as scarce as pickup ones — schedule the empty return in advance.
Return promptly. Don't let empties linger in your yard; a prompt return is the single most reliable way to zero out per diem.

The common thread: fast, coordinated drayage

Almost every avoidance tactic comes back to the same thing — a drayage carrier that moves quickly and communicates clearly. Fast pickups beat demurrage; fast empty returns beat per diem; and transloading or drop-and-pick keeps equipment cycling instead of sitting.

OnTrak is a licensed, insured, hazmat-certified drayage carrier based in Doral, serving PortMiami and Port Tampa Bay with dedicated local teams that watch your free-time clocks so you don't have to. Ready to keep your containers moving? Request a drayage quote and tell us your last free day.