HMM demurrage dispute: what the invoice must show and how to challenge it

What the invoice must show

46 CFR 541.6 says a demurrage or detention invoice must be accurate and, at a minimum, include:

Identifying information: the bill of lading number(s); the container number(s); for imports, the port(s) of discharge; and the basis for why the billed party is the proper party of interest and thus liable for the charge.
Timing information: the invoice date; the invoice due date; the allowed free time in days; the start date and the end date of free time; for imports, the container availability date; for exports, the earliest return date; and the specific date(s) for which demurrage or detention were charged.
Rate information: the total amount due; the applicable rule the daily rate is based on (for example the tariff name and rule number, terminal schedule, or service contract number and section); and the specific rate or rates.
Dispute information: an email, telephone number or other contact for questions or requests for fee mitigation, refund or waiver; a URL, QR code or similar that leads to a public page describing what the billed party must provide; and the timeframes in which the billed party must ask and the billing party will resolve.
Certifications from the billing party that the charges are consistent with the Federal Maritime Commission’s rules on demurrage and detention, and that its own performance did not cause or contribute to the charges.

Source: 46 CFR 541.6 on eCFR , as amended 89 FR 14363 (2024-02-26). The Federal Register notice 90 FR 60579 (document 2025-23920, effective 2025-12-29) says the other provisions of the rule remain in effect.

What a missing item means

Under 46 CFR 541.5 , failure to include any required minimum information eliminates the billed party’s obligation to pay the charge; the FMC’s FAQ adds that the carrier may issue a corrected invoice. So name the missing item in writing, ask for a corrected invoice, and keep the deadline printed on the invoice.

HMM’s own dispute process

HMM’s DEM/DET Tariff (Basic) page sets out its United States dispute resolution:

The billed party has 30 calendar days from the invoice issuance date to ask HMM for mitigation, refund or waiver. HMM tries to resolve a request within 30 calendar days of receiving it, or later if both sides agree.
A dispute should include at least the invoice number, the B/L number and the container number. It should also state the basis, for example invalid free time, invalid rate, invalid term, cargo availability, empty return restriction or government inspection, and include evidence for that basis. One example of evidence is time-stamped screenshots showing that no appointments were available.
HMM’s general approach is to grant relief where the billed party shows the container could not actually be retrieved or returned because of a terminal closure, equipment malfunction, weather or another physical impediment, without fault or negligence of the customer.
Disputes go through HMM’s Invoice Dispute page, or by email to [email protected] (demurrage) or [email protected] (detention).

How to pay

HMM takes US import demurrage payments on its Demurrage Payment page (sign-in required). Its online payment manual and bank information for wire and ACH are linked from the DEM/DET Tariff page.

How Purserhouse checks an invoice

It reads the invoice and lists which of the items above it does not show, only for items it can read from the document.
It compares the free time and the daily rate on the invoice with the carrier’s published US tariff, where we hold it, and flags an invoice only when the amount is above the tariff.
It recomputes the last free day from the discharge or availability date and the free days.
It drafts the dispute letter, a free time extension request or a waiver request, in English, for you to review and send. You can also write one yourself with the demurrage letter tool .

It cannot see your contract with the carrier, so a contract may give more than the tariff. Use the last free day calculator for a quick check, and see what we hold of the HMM tariff .

HMM publishes its own US demurrage and detention tariff and its dispute and payment instructions on its site: https://www.hmm21.com/. We link to it and do not copy it.

Sources

Updated: 2026-10-21