AnalysisDetention and delay · What the clock costs
How much does demurrage cost per day, and why day nine costs more than day six
Published demurrage across US terminals runs between $75 and $300 per container per day, and the number is not flat: carrier tariffs step it up in tiers, so the fourth day past free time bills more than the first. Free time is typically 3 to 7 days. Detention is a separate charge on the same box, billed by the carrier for keeping the equipment, and the two invoices arrive from different parties for the same delay.
Demurrage, detention, storage: four names, one gate
Demurrage is charged for cargo sitting inside the terminal past its free time. Detention is charged for the container staying outside the terminal past its free time. Storage is the terminal's own line for the same occupancy, and per diem is the carrier's word for detention. Which name appears on the invoice depends on who is billing, not on what happened.
The consequence is two invoices for one delay, from two parties, on two clocks. Reconciling them is the first step in any dispute, because the same day can legitimately appear on both.
Why the daily rate is not a daily rate
Carrier US tariffs publish demurrage in tiers. A typical structure charges a low rate for the first band of days past free time, a higher rate for the next band, and a higher one again beyond that. The published band of $75-300 across the 86 pages SeaRates measured spans those tiers rather than describing a flat charge.
The practical effect is that exposure is convex. Four days late is more than twice as expensive as two, and a week is not three and a half times three days. Any estimate built by multiplying a single daily figure understates the tail.
What free time actually depends on
| What sets your free time | Who publishes it | Why it matters |
|---|---|---|
| The carrier's tariff | Ocean carrier | Sets detention and per diem |
| The terminal's tariff | Marine terminal operator | Sets demurrage and storage |
| Your service contract | Carrier, negotiated | Can extend free time; most spot bookings have none |
| The port's own programme | Port authority | Some gateways add or remove days |
Nothing in that list is the country, the commodity or the size of the shipper. Free time is a document question, and the answer is written down before the container arrives.
The rule that can cancel the bill
Since the FMC's final rule on detention and demurrage billing practices took effect on 28 May 2024, an invoice must reach the billed party within 30 days of the charge ceasing to accrue, and must carry 20 specified elements grouped in five categories under 46 CFR 541.6 — identifying information, dates, the rate and its source, the dispute process and a certification.
An invoice missing a required element carries no obligation to pay. Of the 86 pages SeaRates measured on this cluster, 7 explain that rule. It is the single most valuable thing on a demurrage invoice and the market almost never mentions it.
Where this goes next
Three pages carry the rest of this question: the number behind it, the comparison of whoever would do it, and the check that runs before you pay.
- how the demurrage and detention clock runs — the figure behind it
- capacity, reliability and orderbook, ranked separately — who does it
- which credential covers the ocean leg — check the licence
Two neighbouring pieces sit closer to this one than any of them: check before you bargain, and and why no published list can answer it.
Frequently asked questions
How much does demurrage cost per day?
Published US figures run $75 to $300 per container per day across the pages measured on 07/26/2026. The rate is tiered rather than flat, so later days bill higher than the first ones past free time.
How many free days do I get?
Typically 3 to 7 days at US terminals, set by the terminal tariff, the carrier tariff and any service contract. Spot bookings usually carry the tariff minimum.
What is the difference between demurrage and detention?
Demurrage is the cargo sitting inside the terminal past free time. Detention is the container staying outside the terminal past free time. Different parties bill them, and one delay can generate both.
Who pays demurrage charges?
Whoever the carrier or terminal has billed under the contract of carriage — usually the consignee or the party named on the bill of lading. A forwarder billed as the contracting party normally passes it through.
Can a demurrage invoice be unenforceable?
Yes. Under the FMC rule in force since 28 May 2024 the invoice must arrive within 30 days and carry 20 required elements. An invoice missing a required element carries no obligation to pay.
Sources
- Federal Maritime Commission, final rule on detention and demurrage billing practices, in force 28 May 2024 — 30-day invoicing deadline and the 20 required elements under 46 CFR 541.6.
- SeaRates measurement of 86 pages ranking for demurrage and detention queries, 07/26/2026: 7 explain the billing rule.
- Published carrier US demurrage tariffs, tiered by days past free time, read 07/26/2026.