46 CFR 541: what must a demurrage or detention invoice contain?
The FMC billing rule lists the minimum information that a demurrage or detention invoice must carry, in five groups: identifying, timing, rate and dispute information, and two statements by the billing party. By the words of the rule, an invoice that leaves out any of it ends the obligation of the billed party to pay that charge, and so does an invoice issued after the time limit. The sections below quote the rule, give a table to hold your own invoice against, and set out the limits that run for the billing party and for you.
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What the rule says about an item that is missing
This guide takes for granted that the rule covers your invoice: who issued it and what it charges for are in Demurrage vs detention. What follows is what a covered invoice must contain and when it must be issued. The text is 46 CFR part 541 as eCFR shows it, up to date as of October 28, 2026.
Section 541.1 says the part "establishes the minimum information that must be included on or with demurrage and detention invoices" (46 CFR 541.1). The words "on or with" matter when you read an invoice: an item may be printed on it or sent with it, so look at every page and attachment before you decide that an item is not there.
Section 541.5 states the consequence in one sentence: "Failure to include any of the required minimum information in this part in a demurrage or detention invoice eliminates any obligation of the billed party to pay the applicable charge" (46 CFR 541.5). The FMC says the court decision that set aside section 541.4 left the rest of the rule as it was: "all of the provisions of 46 C.F.R. 541 except for section 541.4 are and will remain fully applicable" (FMC).
What section 541.6 requires
Section 541.6 has five paragraphs, (a) to (e) (46 CFR 541.6). Paragraphs (a) to (d) say that the invoice must be "accurate and contain sufficient information" for a stated purpose, and list what it must include at a minimum. Paragraph (e) asks for two statements from the billing party.
| Paragraph | What the rule says it is for | Source |
|---|---|---|
| (a) Identifying information | To "identify the container(s) to which the charges apply". | 46 CFR 541.6(a) |
| (b) Timing information | To "identify the relevant time for which the charges apply and the applicable due date for invoiced charges". | 46 CFR 541.6(b) |
| (c) Rate information | To "identify the amount due and readily ascertain how that amount was calculated". | 46 CFR 541.6(c) |
| (d) Dispute information | To "readily identify a contact to whom they may direct questions or concerns related to the invoice and understand the process to request fee mitigation, refund, or waiver". | 46 CFR 541.6(d) |
| (e) Certifications | Two statements from the billing party. | 46 CFR 541.6(e) |
| Requirement | Source | What to look for on your invoice |
|---|---|---|
| The Bill of Lading number(s) | 46 CFR 541.6(a)(1) | A Bill of Lading number, on the invoice or on a page sent with it. |
| The container number(s) | 46 CFR 541.6(a)(2) | A container number for each container charged, the same as on your own papers. |
| For imports, the port(s) of discharge | 46 CFR 541.6(a)(3) | A port of discharge, if the shipment is an import. |
| The basis for why the billed party is the proper party of interest and thus liable for the charge | 46 CFR 541.6(a)(4) | Words that say why your company is the one billed. |
| The invoice date | 46 CFR 541.6(b)(1) | A date on the invoice itself. |
| The invoice due date | 46 CFR 541.6(b)(2) | A date by which the invoice is to be paid. |
| The allowed free time in days | 46 CFR 541.6(b)(3) | A number of free days. |
| The start date of free time | 46 CFR 541.6(b)(4) | The day free time began. |
| The end date of free time | 46 CFR 541.6(b)(5) | The day free time ends. |
| For imports, the container availability date | 46 CFR 541.6(b)(6) | The date the container became available, if the shipment is an import. |
| For exports, the earliest return date | 46 CFR 541.6(b)(7) | The earliest date the container could be returned, if the shipment is an export. |
| The specific date(s) for which demurrage and/or detention were charged | 46 CFR 541.6(b)(8) | The days charged, as a range of dates or a list of days. |
| The total amount due | 46 CFR 541.6(c)(1) | A total for the invoice. |
| The applicable detention or demurrage rule (e.g., the tariff name and rule number, terminal schedule, applicable service contract number and section, or applicable negotiated arrangement) on which the daily rate is based | 46 CFR 541.6(c)(2) | A tariff name and rule number, a terminal schedule, a service contract number and section, or a named negotiated arrangement. |
| The specific rate or rates per the applicable tariff rule or service contract | 46 CFR 541.6(c)(3) | A rate per day, so that you can multiply days by rate and compare the result with the amount charged. |
| The email, telephone number, or other appropriate contact information for questions or request for fee mitigation, refund, or waiver | 46 CFR 541.6(d)(1) | An email address, a telephone number or another contact. |
| Digital means, such as a URL address, QR code, or digital watermark, that directs the billed party to a publicly accessible website that provides a detailed description of information or documentation that the billed party must provide to successfully request fee mitigation, refund, or waiver | 46 CFR 541.6(d)(2) | A web address, a QR code or a digital watermark, and a page behind it that is open to the public. |
| Defined timeframes that comply with the billing practices in this part, during which the billed party must request a fee mitigation, refund, or waiver and within which the billing party will resolve such requests | 46 CFR 541.6(d)(3) | Two periods stated on the invoice: how long you have to make a request, and how long the billing party has to answer. |
| The charges are consistent with any of the Federal Maritime Commission's rules related to demurrage and detention, including, but not limited to, this part and 46 CFR 545.5 | 46 CFR 541.6(e)(1) | A statement by the billing party to that effect. |
| The billing party's performance did not cause or contribute to the underlying invoiced charges | 46 CFR 541.6(e)(2) | A statement by the billing party to that effect. |
In our sample report, invoice EX-20413 has no web address for dispute requirements, the item of 46 CFR 541.6(d)(2), and no statement that the carrier's performance did not cause or contribute to the charges, the item of 46 CFR 541.6(e)(2). The other items that apply to an import are on it. The invoices of the sample are invented: see the sample report.
The time limits, for the billing party and for you
Section 541.7 sets when an invoice must be issued, and section 541.8 sets how long you must be given to ask for mitigation, refund, or waiver (46 CFR 541.7, 46 CFR 541.8). Each limit is stated as thirty (30) calendar days, but 541.8(a) says "at least" thirty days, 541.8(b) allows "a later date as agreed upon by both parties", and they do not all start from the same date.
| Limit | Who it binds | What the rule says | Source |
|---|---|---|---|
| Issuing the invoice | The billing party | It must issue the invoice "within thirty (30) calendar days from the date on which the charge was last incurred". If it does not, the billed party "is not required to pay the charge". | 46 CFR 541.7(a) |
| An NVOCC issuing its own invoice | An NVOCC that is the billing party | It must issue its invoice "within thirty (30) calendar days from the issuance date of the demurrage or detention invoice it received". | 46 CFR 541.7(b) |
| An NVOCC that is both billed party and billing party | The NVOCC and its billing party | The NVOCC "can inform its billing party that the charge has been disputed by the NVOCC's billed party", and its billing party must then provide an additional thirty (30) calendar days "for the NVOCC to dispute the charge upon this notice". | 46 CFR 541.7(c) |
| Invoicing the wrong person | The billing party | It may issue an invoice to the correct billed party if it does so "within thirty (30) calendar days from the date on which the charge was last incurred". | 46 CFR 541.7(d) |
| Asking for mitigation, refund, or waiver | The billing party must allow it to the billed party | At least thirty (30) calendar days from the invoice issuance date. | 46 CFR 541.8(a) |
| The answer to that request | The billing party | It "must attempt to resolve the request within thirty (30) calendar days of receiving such a request or at a later date as agreed upon by both parties". | 46 CFR 541.8(b) |
Under 46 CFR 541.7(a) the clock runs from the date on which the charge was last incurred, and under 46 CFR 541.8(a) from the invoice issuance date. The window you are given has to be on the invoice too: 46 CFR 541.6(d)(3) asks for "Defined timeframes that comply with the billing practices in this part", one for your request and one for the answer.
In our sample report, invoice EX-20412 is issued 41 days after the last charged day, and invoice EX-20414 allows 14 days to ask for a waiver. They are examples of an invoice outside the limit of 541.7(a) and of a window shorter than 541.8(a) allows, on invented invoices: see the sample report.
How to hold your own invoice against the rule
- Check that the rule covers the invoice: who issued it and what it charges for. The guide on demurrage vs detention explains it.
- Gather the invoice with every page and attachment that came with it, because the rule speaks of information on or with the invoice.
- Go down the table of the items of section 541.6 above and mark each item as found, not found or unclear, with the page you saw it on.
- Count calendar days from the last day charged to the invoice date, and from the invoice date to the end of the window the invoice gives you to ask for a waiver.
- For each line, multiply the days by the rate and compare the result with the amount charged: 46 CFR 541.6(c) asks that you can "readily ascertain how that amount was calculated".
- Keep the list of what you could not find. It is yours to bring to the billing party or to an adviser, and the rule's words on a missing item are in 46 CFR 541.5.
What DemurrageCheck checks and what it does not
- It looks for each of the twenty items of 46 CFR 541.6 on the invoice and on the pages sent with it, and names the paragraph for every item it does not find. The list of checks is on the how it works page.
- It reports an invoice from a carrier or a marine terminal issued more than 30 calendar days after the last day charged (46 CFR 541.7(a)). For an NVOCC it counts from the invoice the NVOCC received (46 CFR 541.7(b)), which it needs from you. It counts the thirtieth day as on time. That is the product's reading of the words "within thirty (30) calendar days", and a reading of the rule is for you and your adviser to confirm.
- It reports a window to ask for a waiver shorter than 30 calendar days from the invoice date (46 CFR 541.8(a)), and an invoice that leaves out the time for a request or the time for the answer (46 CFR 541.6(d)(3)).
- It does not test 46 CFR 541.7(c) or 46 CFR 541.7(d), which need facts that one invoice does not show, and it does not test whether the billing party answered in time under 46 CFR 541.8(b). It emails you a reminder when no answer is recorded and more than 30 days have passed since the date you recorded for sending the request (how it works).
- For an item that is on the invoice it checks that the item is there, not that what it says is right: whether the free time was counted correctly or the rate is the one in your contract needs documents it does not read. The exception is the arithmetic check, which reports an invoice that charges more than the days times the printed rates.
- An item it cannot read with certainty is shown as Needs data and not as a defect.
Sources
- 46 CFR part 541 (eCFR): The text of part 541 as eCFR shows it, up to date as of October 28, 2026
- 46 CFR 541.1, purpose (eCFR): The purpose of the part: the minimum information on or with an invoice
- 46 CFR 541.5, failure to include required information (eCFR): The consequence of leaving out required information
- 46 CFR 541.6, contents of invoice (eCFR): The contents of an invoice: identifying, timing, rate and dispute information, and certifications
- 46 CFR 541.7, issuance of invoices (eCFR): The time limits for issuing an invoice
- 46 CFR 541.8, requests for fee mitigation, refund, or waiver (eCFR): The time to ask for mitigation, refund, or waiver, and the time to answer
- FMC, U.S. Court of Appeals issues decision in case on demurrage and detention billing practices: The rest of part 541 remains in effect after section 541.4 was set aside
- DemurrageCheck, sample report: Invoices EX-20412, EX-20413 and EX-20414 and what the checks report on them (invented invoices)
- DemurrageCheck, how it works: The checks of the product, what is not checked, and the reminders
This guide is general information about a federal rule, not legal advice. DemurrageCheck is software, not a law firm. Read the rule itself for its exact wording.
Next step
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