A US importer we work with opened a container invoice last month and did the thing most shippers do: he forwarded it to accounting for payment. Four figures, a container number, a due date. It looked official. It wasn't compliant. The invoice was missing the specific date and time the container's free time actually ended, so under the Federal Maritime Commission's own rule, he had no legal obligation to pay it as issued. He disputed it in writing, cited the rule, and the ocean carrier reissued a corrected invoice two weeks later for about 40% less.
That gap between what carriers bill and what they're allowed to bill is where a lot of unnecessary demurrage and detention cost sits. GetTransport.com moves freight and matches cargo with carriers, so this is the operational read on the rule, not legal advice. If a dispute turns into a real legal fight, talk to counsel who handles Shipping Act matters. What follows is what our freight desk checks on every D&D invoice before anyone approves payment.
Demurrage vs. detention: the distinction that still trips people up
Demurrage is the charge for keeping a container inside the marine terminal past the free time allowed, whether it's still loaded or not. It's a storage-and-space charge assessed by the ocean carrier or the marine terminal operator. Detention is the charge for keeping the carrier's equipment, the container and chassis, outside the terminal past the allowed free time, typically while it sits at a warehouse or distribution center waiting to be unloaded and returned empty.
The simplest way our desk explains it to new shippers: demurrage is about the box sitting in the terminal, detention is about the box sitting anywhere else once it has left the terminal gate. Free time windows vary by port, carrier, and contract, commonly somewhere in the 3 to 5 day range at major US gateways, but there is no single national standard free-time number, so check the applicable tariff or service contract for each move rather than assuming a figure.
Where the rule actually comes from
The Demurrage and Detention Billing Requirements rule is a direct product of the Ocean Shipping Reform Act of 2022 (OSRA-22), which gave the FMC a mandate to define what a legitimate D&D invoice has to contain. The Commission published the final rule in the Federal Register on 26 February 2024, and it took effect on 28 May 2024 for most provisions. The invoice-contents section, 46 CFR 541.6, needed separate approval under the Paperwork Reduction Act and became enforceable on the same 28 May 2024 date once that review cleared.
The rule sits in 46 CFR Part 541 and applies to vessel-operating common carriers (VOCCs), non-vessel-operating common carriers (NVOCCs), and marine terminal operators. It does not apply to trucking companies as billing parties, and it does not set the actual dollar rate anyone can charge for demurrage or detention. According to the Federal Maritime Commission, the rule governs billing practices and invoice content, not pricing.
What a compliant invoice has to contain
Under 46 CFR 541.6, an invoice has to give the billed party enough information to independently verify three things: which container the charge applies to, what time period the charge covers, and how the dollar amount was calculated. In practice, that means the invoice needs to show, at minimum:
- The specific container number(s) the invoice covers, tied to a bill of lading or booking number
- The invoice date and the invoice due date
- The specific date and time that free time began and the date and time it ended
- The applicable per-diem rate or rates, tied to the specific tariff rule or service contract provision being charged
- The total amount due and how it was calculated from the rate and time period
- The basis for why the billed party is the party responsible for the charge
- Contact information for disputing the invoice or requesting mitigation, a refund, or a waiver, which the rule allows to be delivered via a URL, QR code, or digital watermark rather than printed text
Failing to include any one of these elements is not a technicality. Under the rule, an invoice missing required data eliminates the billed party's obligation to pay the charge as billed. That is the single most useful sentence in the whole regulation for a shipper's AP team to know.
Who can actually be billed, and why that changed in 2025
When the rule was first written, 46 CFR 541.4 limited D&D billing to just two parties: the entity that contracted directly with the carrier for ocean transportation, or the consignee, generally not both on the same charge. The intent was to stop carriers from billing motor carriers who never had a contract with them, since a drayage company can't control how long a beneficial cargo owner takes to unload a container.
That changed in 2025. The US Court of Appeals for the D.C. Circuit ruled on 23 September 2025 in World Shipping Council v. FMC that Section 541.4 was arbitrary and capricious, because the Commission's blanket ban on billing motor carriers was inconsistent with the rest of the rule's own contract-based logic, particularly since consignees could still be billed with no contractual privity at all. The court vacated the section with immediate effect. In the current Code of Federal Regulations, as it stands in 2026, Section 541.4 is marked reserved and no longer applies, while the rest of Part 541, including the invoice-content and timing rules, was left untouched.
The practical result as of mid-2026: there is currently no bright-line federal rule dictating exactly who a carrier may or may not invoice for demurrage or detention. Motor carriers are back in a gray zone rather than a protected one. The rest of Part 541, meaning the invoice-content requirements in 541.6 and the billing and dispute timelines in 541.7 and 541.8, was not touched by the court's decision and remains fully in force. The billed-party fight isn't over either: the FMC could issue a new rule with better justification, so this is a live area to watch, not settled law. Don't assume your contract's allocation of D&D risk is backed up by a federal billing restriction right now; it isn't.
The clock: billing and dispute windows
Under 46 CFR 541.7, the billing party has 30 calendar days from the date charges stopped accruing to issue the invoice. An NVOCC that is itself billed by an ocean carrier gets 30 calendar days from receiving that upstream invoice to pass its own invoice down to its customer. Invoices issued outside that window are themselves a rule violation.
Under 46 CFR 541.8, once a compliant invoice is issued, the billed party has at least 30 calendar days from the invoice date to submit a request for fee mitigation, a refund, or a waiver. The billing party then has 30 calendar days after receiving that request to resolve it, unless both sides agree in writing to extend the timeline. If the billing party misses its 30-day window to respond, that is itself a basis to escalate.
How to read an invoice before you pay it
The most common mistake we see is paying an invoice that fails the FMC's own data-element test simply because it looks routine. Before approving any D&D invoice, our freight desk runs through the same short list every time: does it name the exact container and reference a bill of lading, does it show the actual date and time free time expired rather than just a generic date range, does it show the per-diem rate and cite the tariff rule or contract clause behind it, and does it explain why your company specifically is the liable party rather than just assuming it. If any of those are missing or vague, that is grounds to dispute, not a reason to just pay and move on.
It's worth being clear on what the rule does not do. It does not cap demurrage or detention rates, it does not forgive legitimate charges that are properly documented, and it does not give a billed party unlimited time to dispute; miss the 30-day mitigation-request window and you've generally lost that avenue. The rule is a floor on transparency, not a shield against every charge.
Reducing D&D exposure operationally
The billing rule helps you catch bad invoices, but the cheaper fix is not generating the charges in the first place. A few things that consistently move the needle for shippers we work with: booking drayage capacity before the vessel arrives rather than after, so a truck is available inside the free-time window instead of a week later; tracking container availability and customs status daily rather than waiting for a demurrage notice to check; and building buffer into delivery appointments at the distribution center so a container isn't sitting on a chassis outside the warehouse for days because the dock has no open slot.
For shippers managing landed cost more broadly, how you structure the underlying trade terms also matters, since who is contractually positioned to receive and dispute a D&D invoice often traces back to the Incoterms on the shipment; see our breakdown of Incoterms DDP vs DAP and who pays what for how that allocation works. For importers who chronically fight the free-time clock because customs clearance or distribution isn't ready the moment a container lands, a bonded warehouse strategy can take pressure off the demurrage window entirely by giving cargo a compliant place to sit while duties and paperwork catch up.
FAQ
Do I have to pay a demurrage invoice while I'm disputing it?
Not automatically, and this is one of the more misunderstood parts of the rule. If the invoice itself fails to include the required data elements under 46 CFR 541.6, the billed party has no obligation to pay the charge as billed in the first place. If the invoice is compliant but you believe the charge is wrong on the merits, for example because free time was miscalculated or the container was actually available for pickup earlier than claimed, you can submit a written request for mitigation, refund, or waiver within the 30-day window under 541.8 rather than paying and hoping for a later credit. Keep records of terminal availability, appointment confirmations, and any port congestion notices, since those are what actually support a dispute.
Can an ocean carrier bill my trucking company directly for detention?
As of the D.C. Circuit's September 2025 decision in World Shipping Council v. FMC, which vacated Section 541.4 with immediate effect, the specific federal restriction that used to block this was removed. There is currently no standing FMC rule that categorically prevents a carrier from invoicing a motor carrier, so this now depends more heavily on the actual contractual relationships in the transaction and is an area where the FMC may issue new guidance. If your drayage provider is billed for a delay it did not control, the underlying facts and your service contract terms matter more than ever.
What counts as a "required data element" if the invoice looks normal?
Looking normal and being compliant are different things. The rule requires the invoice to let you independently verify the container identity tied to a bill of lading, the exact date and time free time started and ended, the specific rate and the tariff or contract provision it comes from, the total calculated amount, why your company is the liable party, and how to reach someone to dispute it. A lot of invoices show a lump sum and a due date without the underlying date-and-time detail or rate citation, which is the single most common compliance gap our freight desk finds.
Does OSRA-22 apply to imports and exports both?
Yes. The Ocean Shipping Reform Act of 2022 and the billing rule that followed from it apply to demurrage and detention charges on both inbound and outbound US cargo, and to invoices issued by VOCCs, NVOCCs, and marine terminal operators alike. The mechanics of free time, invoice timing, and dispute windows under 46 CFR Part 541 don't change based on trade direction, though the operational triggers, like export container pickup delays versus import unloading delays, look different in practice.