The two clocks, side by side
| Demurrage | Detention (per diem) | |
|---|---|---|
| Where | Inside the terminal / port | Outside the terminal — your yard, warehouse, drayage |
| Clock starts | When free time ends after discharge / availability (terms vary — check yours) | When the container gates out |
| Clock stops | When the container gates out | When the empty is returned |
| Typical cost | Escalating per-day tiers — routinely $75–$300+/day | Per-day equipment charge — commonly $50–$150+/day |
Why the invoices are so often wrong
Because the correct charge lives in your documents, and the invoice is generated from the carrier's defaults. The usual failure points:
- Wrong free time. Your rate agreement negotiated 7 days; the invoice assumes the tariff default of 4.
- Wrong clock start. Terms differ on whether the clock starts at discharge, at availability, or the day after — and the difference is billable days.
- Days that shouldn't count. Terminal closures, holidays, and days the container wasn't actually available often pause the clock — if anyone checks.
- Wrong rate tier. Escalating tiers applied from the wrong start date compound the error.
None of this is exotic. It's a date-and-clause reconciliation problem — the same family of leak as freight invoice audit errors generally, where industry audits keep finding meaningful error rates.
How to dispute — with your own documents
- Pull the governing clause. Your rate agreement or service contract states free time and per-day rates. Quote it — section and page.
- Rebuild the timeline. Availability notice, gate-in/gate-out receipts, empty-return interchange. Line the invoice's dates against them.
- Strike the days that don't count. Closures, holidays, unavailability — with the notices that prove them.
- State the corrected amount and dispute in writing within the carrier's dispute window (they're short — often 30 days).
§4.2 (p. 11), free time is 7 calendar days from availability. Availability notice is dated June 2; gate-out June 8 — day 6. The invoiced 4 days of demurrage are not owed. Corrected amount: $0."The dispute that doesn't: "We believe this charge is incorrect, please review."
Doing this without burning an afternoon per invoice
The reason teams pay wrong invoices isn't that disputes fail — it's that reconciling every charge against the rate agreement and gate records takes hours nobody has. That lookup is exactly what IntelMS for logistics does by email: "what's our free time with this carrier, and does this invoice match?" answered in minutes from your own uploaded agreements and shipment documents, with the clause and page cited — and anything money-decision-grade routed to a human, never auto-approved. See how its answers cite and decline.
Stop donating to your carrier
14-day free pilot. Upload a rate agreement and one disputed invoice; ask the question you'd ask your best ops person. Judge the citation yourself.
Start a free pilot