Charges
Demurrage and detention invoices: what to check and how to dispute
Demurrage and detention charges are among the most disputed bills in container shipping, largely because they depend on dates that different parties record differently. In the US, the Federal Maritime Commission's billing rule sets out what an ocean carrier's or terminal's invoice must contain. The rest depends on your own records of when containers were available, picked up and returned.
Not legal advice. This summarizes the FMC's billing rule at 46 CFR Part 541 as published, and general practice. Your service contract, the carrier's tariff and the terminal's schedule set the actual free time and rates. Check the current rule text and take advice on large disputes.
Demurrage vs detention
| Demurrage | Detention | |
|---|---|---|
| Usually charged for | A container that stays inside the terminal beyond its free time | A container (and sometimes chassis) kept outside the terminal beyond its free time |
| Clock usually starts | When the import container is available for pickup | When the container leaves the terminal |
| Clock usually stops | When the container leaves the terminal | When the empty (or loaded export) container is returned |
Usage varies by carrier and country; some combine both into one charge. Read the tariff or contract definition, not the label on the invoice. Trucking "detention" for a truck kept waiting at a dock is a different charge, covered at the end of this guide.
What the FMC rule requires on an invoice
The FMC's rule on demurrage and detention billing, 46 CFR Part 541, took effect on May 28, 2024. It applies to demurrage and detention invoices issued by ocean common carriers, marine terminal operators and NVOCCs, but not to billing between carriers and terminals themselves (541.2). Under 541.6, an invoice must include at least:
| Group | Minimum information |
|---|---|
| Identifying | Bill of lading number(s); container number(s); for imports, port(s) of discharge; the basis for why the billed party is the proper party |
| Timing | Invoice date; due date; allowed free time in days; start and end dates of free time; for imports, the container availability date; for exports, the earliest return date; the specific dates charged |
| Rate | Total amount due; the tariff rule, terminal schedule or contract provision the rate comes from; the specific rate or rates |
| Dispute | Contact information for questions and fee mitigation, refund or waiver requests; a link or code to a public page describing what to submit; the timeframes for requests and for resolving them |
| Certifications | Statements that the charges are consistent with the FMC's demurrage and detention rules, and that the billing party's own performance did not cause or contribute to the charges |
Under 541.5, failure to include any of the required minimum information eliminates the billed party's obligation to pay the charge.
Timing rules in the billing regulation
- Invoice within 30 days. The billing party must issue the invoice within 30 calendar days of the date the charge was last incurred, or the billed party is not required to pay (541.7(a)). An NVOCC passing on a charge has 30 days from the invoice it received (541.7(b)).
- At least 30 days to dispute. The billed party must be allowed at least 30 calendar days from the invoice date to request mitigation, refund or waiver (541.8(a)).
- Attempt to resolve within 30 days. The billing party must try to resolve a request within 30 calendar days of receiving it, or later if both agree (541.8(b)).
In September 2025 the US Court of Appeals for the D.C. Circuit set aside one section of the rule, 46 CFR 541.4, which had limited who an invoice could be sent to. According to the FMC, the rest of the rule remains in effect. Check the FMC's site for later developments.
Invoice review checklist
- Is every required field present? Go through the table above.
- Was it issued within 30 days of the last day charged?
- Are you the right party? Check the stated basis against the bill of lading and your contracts.
- Does the free time match your service contract, not just the public tariff?
- Does the availability date match reality? Compare with terminal records, holds and appointment availability.
- Were there days you could not act? Customs or other holds, terminal closures, no appointments, or no place to return the empty.
- Are the dates and rates arithmetically right? Recalculate.
- Diary the dispute deadline from the invoice date.
Records to keep for every container
| Event | Record |
|---|---|
| Vessel discharge and availability | Terminal status and time, any holds and when they were released |
| Appointment attempts | Screenshots or logs showing no appointments were available |
| Gate out | Terminal gate record (interchange), trucker, chassis |
| Delivery and unloading | Proof of delivery, time emptied |
| Return attempts | Evidence that return locations would not accept the empty |
| Gate in | Terminal or depot gate record for the return |
Most disputes come down to one date. Keep the gate records, holds and appointment evidence against the container in the same place as the rest of the shipment's history. The custody guide explains why one record with every party's reference saves time here.
How to dispute
- Use the dispute channel stated on the invoice, within its timeframe.
- Identify the invoice, containers and specific days disputed.
- State the grounds: missing required information, late invoice, wrong party, wrong free time, or days on which the container could not be picked up or returned.
- Attach the evidence, dated.
- Keep a record of the request and the response. If the dispute is not resolved, the FMC has complaint and assistance processes; check its site for current options.
Detention in trucking
Truck detention, charged when a driver waits beyond the agreed free time at a shipper or receiver, is set by the carrier's rate confirmation or contract rather than by the FMC rule. The same principle applies: the charge is only as good as the arrival and departure times behind it. Record check-in and check-out times on the bill of lading or proof of delivery, and keep any gate or electronic records that confirm them. Detention time records covers what a defensible arrival and departure record contains, and why an electronic logging device alone cannot separate waiting from loading.
Common questions
What is the difference between demurrage and detention?
Demurrage usually applies to containers kept at the terminal beyond free time; detention to containers kept outside the terminal beyond free time. Definitions vary, so check the tariff or contract.
How long does a carrier have to send a demurrage invoice in the US?
Under 46 CFR 541.7, 30 calendar days from the date the charge was last incurred. If it misses that window, the billed party is not required to pay.
How long do I have to dispute?
The billing party must allow at least 30 calendar days from the invoice date. The invoice should state the actual timeframe.
Does the FMC rule cover trucking detention?
No. It covers demurrage and detention billed by ocean carriers, marine terminal operators and NVOCCs. Trucking detention is governed by the trucking contract.
Last reviewed 2026-09-17