Three charges cause most of the confusion in drayage. They sound alike, but each is for something different and comes from a different party.
| Charge | What it’s for | Who usually sets it |
|---|---|---|
| Demurrage / terminal storage | A loaded container staying at the terminal past its free time | The steamship line and/or marine terminal, under their tariff |
| Per diem (container detention) | Keeping the steamship line’s container outside the terminal past its free days, until the empty is returned | The steamship line, under its tariff or your service contract |
| Driver detention / waiting time | Keeping the truck and driver waiting at a pickup or delivery beyond the included time | The trucker, under its accessorial schedule |
The names vary. Some carriers say “detention” when they mean container per diem. The Federal Maritime Commission (FMC) uses “demurrage or detention” for charges, including per diem, that ocean carriers, marine terminals and NVOCCs assess for using terminal space or containers. Always check which charge an invoice refers to.
Chassis rental is a separate daily charge again. See chassis days.
Last free day (LFD)
The last free day is the last day an import container can stay at the terminal before storage (demurrage) starts. The free time comes from the applicable tariff or agreement, and the date can change, for example because of holds or terminal closures.
Picking up before the LFD is usually the cheapest outcome. When that isn’t possible, a prepull can help. For exports, the matching dates are the earliest return date and the port cutoff.
Why these can’t be quoted as fixed amounts
Whether you pay, and how much, depends on events that haven’t happened yet:
- when the container is released;
- appointment availability;
- how long unloading takes;
- when the empty can be returned.
Rates and free time come from the applicable tariff or agreement. Some charges are billed directly to you by the steamship line or terminal rather than by us. So on a DK Express quote they appear under possible additional charges, with the terms that apply, never as a guaranteed number.
Your rights on demurrage and detention invoices
The FMC’s billing rule (46 CFR Part 541) took effect on May 28, 2024. It applies to invoices from ocean carriers, marine terminal operators and NVOCCs, not to a trucker’s own waiting-time charges. Among its requirements:
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30 days to invoice. The invoice must be issued within 30 calendar days of the date the charge was last incurred. If it isn’t, the billed party doesn’t have to pay.
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Required information. Among other things, the invoice must show:
- the bill of lading and container numbers;
- the free time allowed, with its start and end dates;
- the container availability date (imports) or earliest return date (exports);
- the dates charged;
- the rate and the tariff or contract rule that applies;
- a contact and instructions for disputing the charge.
Leaving out required information removes the obligation to pay.
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Time to dispute. You get at least 30 calendar days from the invoice date to request a mitigation, refund or waiver. The billing party should try to resolve it within 30 days of your request.
In September 2025 a federal appeals court set aside one section of the rule, the one that limited who may be sent these invoices. The FMC says the rest of the rule remains in effect. Who can be billed now depends on the contracts and tariffs involved, so check your bill of lading and agreements. This is general information, not legal advice.