What the rule covers
The rule is 46 CFR Part 541. It applies to demurrage and detention invoices from ocean common carriers, including NVOCCs, and from marine terminal operators. It treats any charge for the use of terminal space or shipping containers as demurrage or detention, per diem included, while freight charges fall outside it. The FMC published the rule on February 26, 2024, and it has applied in full since May 28, 2024.
- The regulation: 46 CFR Part 541
- In effect since May 28, 2024
- Per diem counts as detention under the rule
The 30-day invoice deadline
A billing party must issue a demurrage or detention invoice within 30 calendar days of the date the charge was last incurred. If it misses that window, the billed party is not required to pay the charge. An NVOCC passing on a charge it was billed has 30 days from the invoice it received. When an invoice went to the wrong party, the corrected invoice must still go out within the original 30 days.
- Count 30 calendar days from the last day the charge accrued
- A late invoice does not have to be paid
- A corrected invoice gets no extra time
What every invoice must show
The rule sets a minimum list of details in five groups, and an invoice that leaves out any required item removes the billed party's obligation to pay the charge.
- Identification: the Bill of Lading and container numbers, the port of discharge for imports, and why the billed party is liable
- Timing: the invoice and due dates, the free days allowed, when free time started and ended, the availability date for imports or the earliest return date for exports, and the dates charged
- Rates: the total due, the tariff rule or contract term behind the rate, and the rate itself
- Disputes: a contact, a link or code to the dispute instructions, and the time limits for disputing
- Certifications: that the charges follow FMC rules, and that the billing party's own performance did not cause them
How to dispute a charge
The billing party must allow at least 30 calendar days from the invoice date to request mitigation, a refund or a waiver, and it must try to resolve a request within 30 days of receiving it, or later if both sides agree. An NVOCC whose own customer disputes a charge can tell its billing party, which must then give the NVOCC another 30 days to dispute. A charge complaint can also be filed with the FMC by email to chargecomplaints@fmc.gov. Under the Ocean Shipping Reform Act of 2022, the carrier bears the burden of showing that a demurrage or detention charge is reasonable.
What changed in 2025
As first written, the rule also limited who could be billed: the party that contracted for the transportation or storage, or the consignee, but not both. On September 23, 2025, the U.S. Court of Appeals for the D.C. Circuit set that section aside, and the FMC removed it from the regulations effective December 29, 2025. The rest of Part 541 still applies, including the deadlines and the required invoice contents, and an invoice must still explain why the party receiving it is liable.
Check the dates against the shipment record
Most invoice questions come down to dates: when the container became available, when it left the terminal and when the empty went back. Compare the free-time start and end dates and the charged dates on the invoice with the milestones in your own records. CargoScope keeps each shipment's carrier milestones in a saved timeline, so a team can check discharge, gate-out and empty-return dates without another carrier lookup and print the shipment's journey as a PDF.
Example workflow
A logistics team adds a container number, follows the milestones and the latest carrier ETA in CargoScope, gets an email when the container reaches the destination port, and uses the at-risk flags on the dashboard to prioritize the next customer or operations update. The workflow is intentionally practical: start with the container, identify what changed, decide whether the shipment needs action, and keep the team aligned on the same record.
Operational checklist
Use the guide to define what your team should review daily: active containers with changed ETAs, shipments approaching port availability or last-free-day risk, containers with holds or missing milestones, and customers waiting on updated delivery timing. A good container visibility process should reduce repeated manual checks, not create another inbox for status noise.
- Review changed ETAs before customer update meetings
- Flag containers that may affect drayage, warehouse labor, or delivery appointments
- Choose the reference that matches the work: container, Bill of Lading, or a supported booking number
How CargoScope supports the work
CargoScope supports container, Bill of Lading, and selected booking-number tracking. It centralizes confirmed milestones, carrier ETA changes, delay signals, and exception context so operators spend less time switching between carrier portals.
Track a container
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Official sources
Questions
Who is this guide for?
It is written for freight forwarders, shippers, importers, exporters, logistics managers, and operations teams improving ocean container visibility.
Can CargoScope track by Bill of Lading?
Yes. Bill of Lading tracking is included with every active paid plan and requires a supported shipping line. CargoScope keeps discovered child containers under the B/L so each journey remains specific.
What problem should this workflow solve?
The goal is to reduce repetitive status checks, catch shipment changes earlier, and help freight teams prioritize containers that affect customers, drayage, warehouses, or avoidable accessorial cost exposure.