Demurrage & detention dispute letter: free template + what actually needs to be in it

Before you write: the two clocks

• Their clock: the billing party must issue a D&D invoice within 30 calendar days from when the charge was last incurred, or you are “not required to pay the charge” (46 CFR § 541.7(a)). Check the invoice date against when charges stopped accruing before anything else.
• Your clock: you must be given at least 30 calendar days from the invoice issuance date to request mitigation, refund, or waiver, and the billing party must attempt to resolve your request within 30 calendar days of receiving it (46 CFR § 541.8). Don't sit on a disputed invoice.

The three arguments, strongest first

1. The math is wrong. Recompute the last free day from the availability (or gate-out) date plus your contractual free days, and check whether billed days include weekends, holidays, or closure days when the terminal wasn't operating. State your recomputation with specific dates. This is the argument carriers can verify fastest, so lead with it.
2. The invoice is missing required content. Compare it against the minimum contents in 46 CFR § 541.6 (identifying, timing, rate, and dispute information — see our full checklist). If something required is missing, § 541.5 says that “eliminates any obligation of the billed party to pay the applicable charge.” Quote the section, name the missing item.
3. The charge can't serve its incentive purpose. The FMC's interpretive rule (46 CFR § 545.5) evaluates D&D practices against their purpose as incentives to move freight. It says, for example, that absent extenuating circumstances, imposing detention when empty containers cannot be returned is “likely to be found unreasonable.” This is a reasonableness standard applied case-by-case — not an automatic exemption — so pair it with evidence: closure notices, appointment system screenshots, gate records.

Sample letter

Replace every bracketed field, delete the numbered sections that don't apply to your facts, and attach your documentation. Only claim what your records support.

[Your name]
[Your company]
[Email · phone]

[Date]

[Carrier name] — Billing / Dispute Department
Re: Request for fee mitigation, refund, or waiver — Container [CONTAINER NO],
Invoice [INVOICE NO] dated [INVOICE DATE]

To whom it may concern,

We are disputing [DOLLAR AMOUNT] in [demurrage/detention] charges billed for
container [CONTAINER NO] and request mitigation, refund, or waiver under the
process required by 46 CFR § 541.6(d).

1. Recomputed free time. The container's [availability/gate-out] date was
[START DATE]. With [N] contractual free days, the correct last free day is
[CORRECT LFD], not [INVOICE LFD] as invoiced. Of the [X] days billed, [Y]
fell on [weekends / terminal closure days] when pickup was not possible.
The correct chargeable total is [CORRECT AMOUNT]; we were billed [BILLED
AMOUNT], a difference of [DIFFERENCE].

2. [If applicable] Missing required invoice content. The invoice does not
include [MISSING ITEM(S)], which 46 CFR § 541.6 requires at a minimum.
Under 46 CFR § 541.5, failure to include required minimum information
"eliminates any obligation of the billed party to pay the applicable
charge."

3. [If applicable] Charges during inaccessibility. Charges were assessed for
[DATES] when [the terminal was closed / no appointments were available /
the container was not available for retrieval]. Under the Commission's
interpretive rule, 46 CFR § 545.5, demurrage and detention are evaluated
against their purpose as incentives; charges assessed when retrieval or
return is not possible do not serve that purpose.

Supporting documentation is enclosed: [invoice copy, terminal availability
/ gate records, appointment screenshots, contract/tariff free-time terms].

Per 46 CFR § 541.8, we submit this request within the dispute window and
ask that you attempt to resolve it within 30 calendar days of receipt.
Please confirm receipt and reply to [EMAIL].

Sincerely,
[Name, title, company]

What makes disputes stick

Specific dates and documents. A letter that says “the charges seem excessive” goes nowhere; a letter that says “June 13–14 were a Saturday and Sunday on which the terminal's gate was closed, so they cannot be chargeable days; corrected total $925.00 vs. $1,295.00 billed” gives the carrier's billing team something they can approve. Send it in writing to the dispute contact the invoice is required to provide (46 CFR § 541.6(d)), keep proof of the date you sent it, and calendar a follow-up for 30 days out.