Demurrage vs Detention

How the FMC defines demurrage and detention

The Federal Maritime Commission does not separate the two words. Its interpretive rule, 46 CFR 545.5, and its billing rule, 46 CFR 541.3, define them together as any charges, "including 'per diem'," assessed by ocean carriers, marine terminal operators and ocean transportation intermediaries "related to the use of marine terminal space (e.g., land) or shipping containers, not including freight charges." The everyday split follows those two halves: demurrage pays for the terminal's land, detention for the line's box. On a NY/NJ container drayage move, demurrage has to be paid before the terminal releases the box, and per diem runs until the trucker returns the empty.

The interpretive rule, adopted May 18, 2020, says the FMC judges these charges by whether they work as "financial incentives to promote freight fluidity." It names four applications of that test: whether demurrage and free time are tied to cargo actually being available for pickup; whether detention is charged when empties cannot be returned, which absent extenuating circumstances is "likely to be found unreasonable"; how and when the cargo owner was told the box was available; and how charges are handled during government inspections.

The billing rule, 46 CFR 541 (89 FR 14362, February 26, 2024), governs the invoices. One section did not survive: in World Shipping Council v. FMC (No. 24-1088, decided September 23, 2025) the D.C. Circuit set aside 541.4, which had limited who could be billed, and the FMC removed it effective December 29, 2025. Lines and terminals can again bill the trucker, who then bills the shipper. The rest of the rule, including the 30-day deadlines below, still applies. This is general information, not legal advice.

How many free days before demurrage at NY/NJ terminals?

Four for dry containers (and for tanks under the NYTC tariff); two for reefers, flat racks, platforms and open tops. The NYTC tariff, used by APM Terminals Elizabeth, PNCT, both Port Liberty terminals and Red Hook, skips Saturdays, Sundays and ILA holidays unless the gate is open. Maher counts working days, meaning any day its gate is open for deliveries. Under both, free time starts at gate opening on the first business day (at Maher, working day) after the container's first point of rest is recorded in the terminal's system, not on the day its holds clear.

The open-gate rule matters on holidays. On Columbus Day, October 12, 2026, PNCT opened from 6 AM to 3 PM, so the day counted toward free time there; Port Liberty Bayonne was closed, so it did not.

Worked example: a 40 ft dry box picked up six days after its last free day owes $1,518 at an NYTC terminal (4 × $231 + 2 × $297) and $1,470 at Maher. A flat rack six days late at an NYTC terminal owes $3,387 (3 × $459 + 3 × $670), which is why out-of-gauge pickups are booked before the ship arrives; see our page on flat rack and open top pickups.

These are the terminals' own rates. Where an ocean line publishes its own demurrage, its tariff applies instead: Maher lists ACL, APL, CMA CGM, COSCO, Evergreen, Hapag-Lloyd, Marfret, ONE, OOCL, Yang Ming and ZIM as setting their own import demurrage, and since June 2024 Hapag-Lloyd, COSCO, OOCL, ONE, Yang Ming and ZIM collect it themselves at Maher. Free time stretched to 10 days or more under a service contract is billed at the top tier (NYTC) or third tier (Maher) from the day it ends.

What a demurrage or detention invoice must include

46 CFR 541.6 lists the minimum contents. If any item is missing, the billed party has no obligation to pay the charge (541.5).

Two deadlines go with it. The invoice must go out within 30 calendar days of the date the charge was last incurred, or the billed party does not have to pay (541.7(a)); an NVOCC passing on a bill has 30 days from the bill it received, and a bill sent to the wrong party can be corrected only inside the same 30 days. The billed party then gets at least 30 calendar days from the invoice date to ask for mitigation, a refund or a waiver, and the billing party must try to resolve the request within 30 days (541.8).

How to dispute a demurrage or detention invoice

1. Check the invoice. Compare it with the 541.6 list above and the date the charge was last incurred. A missing item or an invoice issued after 30 days means no obligation to pay.
2. Collect the evidence. The availability date, the EIRs, appointment screenshots, terminal closure notices and the line's own notices.
3. Send the request to the billing party within 30 days. Maher takes requests at [email protected] within 30 calendar days of the invoice, with the container and bill of lading numbers, vessel and voyage, the line that issued the bill of lading, confirmation that no holds remain, the dates contested, the amount, the reasons and your documents; it aims to decide within 2 business days. Port Liberty takes them at [email protected] within 30 days, with the container number, why it was not picked up in free time, the ocean bill of lading and a certified commercial invoice.
4. For per diem billed to your trucker, give the trucker your evidence: under the UIIA it must dispute in writing within 30 days.
5. If an ocean carrier will not resolve it, file a charge complaint with the FMC. Under the rule effective September 1, 2026 (91 FR 56053), a complaint can go to an Administrative Law Judge or the Small Claims Officer, and the carrier bears the burden of showing its demurrage or detention charge is reasonable.