An invoice arrives for a container that has already been delivered. It is headed "detention", or "demurrage", or "D&D" (demurrage and detention), and the amount grows with every day in a column you did not expect. Before you can decide whether to pay, query or prevent it next time, you need to know which clock produced it.
Short answer. Demurrage is usually charged for the use of a container inside the terminal beyond the free time allowed. Detention is usually charged for the use of the container outside the terminal or depot beyond its free time, typically from gate-out until the empty is returned. UN Trade and Development (UNCTAD), demurrage and detention charges Some carriers combine the two into one charge, and terminals may bill storage separately under their own tariff. Several of the decisions that shorten these clocks are made before the vessel arrives.
This article concerns container charges at ports. A shipowner's claim for delay to a chartered vessel is also called demurrage, but it is a different charter-party concept: an agreed amount payable once the agreed laytime has expired. Laytime Definitions for Charter Parties 2013, definitions 5 and 30
Two charges, two clocks and a third bill
The line owns or controls the container. The terminal controls the space it occupies. That split explains most of the vocabulary.
| Demurrage | Detention | Terminal storage | |
|---|---|---|---|
| What is being paid for | Use of the container inside the terminal beyond free time | Use of the carrier's container outside the terminal beyond free time | Occupation of terminal space under the terminal's own tariff |
| Typical start | Discharge from the vessel (import) | Pickup (gate-out) of the full container | As set by the terminal tariff |
| Typical stop | Pickup (gate-out) | Empty return at the designated place | Removal from the terminal |
| Typically billed by | The carrier | The carrier | The terminal operator, or passed on by an agent |
| Evidence you need | Discharge date, availability date, customs and release history | Gate-out time, unloading time, depot appointment record | Terminal tariff edition, dates in and out |
The first two columns follow carrier and UNCTAD descriptions; the exact start and stop events are set by the governing tariff or contract. Maersk, for example, describes demurrage as running from unloading from the vessel until pickup, and detention from pickup until the container is returned. Maersk, demurrage, detention and free time
Terminology varies by carrier and country. OOCL states that for several Middle East countries, including Saudi Arabia, Oman and Qatar, it combines inbound line detention and demurrage under the single name "detention", and that for the UAE it has combined inbound and outbound line detention and demurrage, which it calls "DD2in1", since 23 November 2019. The same page says that port storage charges in the Middle East countries where it operates are settled by consignees directly with the port or terminal operator. OOCL, Middle East D&D terminology
US regulation uses one combined term, "demurrage or detention", which includes charges described as per diem. eCFR, 46 CFR 541.3
So read the invoice heading as a label, not a definition. Ask which tariff or service-contract clause it applies, which event started the clock and which event stopped it.
When each clock runs, and why the calendar matters
Holiday and weekend treatment is a tariff term, not a universal rule. Two published carrier examples show how far it can differ:
- Maersk's 2020 UK notice counted free time and charges in calendar days, and stated that New Year, Easter and Christmas holidays count unless they fall within the free time. Maersk UK notice, 2020
- Hapag-Lloyd's US notice effective 1 September 2024 kept free time in working days, but after free time expired every scheduled terminal closure day, including weekends, became chargeable. Hapag-Lloyd, calendar-days notice, August 2024
Both are dated, carrier-specific examples, not a description of current practice everywhere. The practical point holds under either approach: if your broker, bank or customs office is closed while the tariff clock runs, days can pass with nobody working on the file. Under calendar-day free time, a vessel discharging just before a long weekend or public holiday can use a large part of the allowance before the first working day.
Before the vessel arrives, get three answers in writing from the carrier or your forwarder: how free time is counted, which days are chargeable after it expires, and which event ends each clock at this port.
Free time is set before the cargo moves
Free time is the number of days allowed before charges begin. It comes from the carrier's published tariff or your service contract, and it can differ between demurrage and detention, between container types and between ports.
Some carriers sell extended free time; Maersk, for example, offers a product that extends free days after pickup from the port. Maersk, free time extension Among recommended practices from FIATA, the international federation of freight forwarders' associations, UNCTAD reported longer detention free periods and an extension of free time when a terminal is unable to release or receive a container. UNCTAD These are recommendations, not binding rules. The practical negotiating moment is at quotation or booking, when you still have alternatives. Once the container is discharged, you are usually asking for a waiver rather than negotiating a term.
Do not plan from another importer's free-time figure or a marketing number. Plan from the tariff or contract clause that applies to your booking.
Why day fifteen can cost more than day five
Some tariffs charge in rising bands after free time: one daily rate for the first band, a higher rate for the next. APL's 2018 notice for UAE ports, for example, set combined import demurrage and detention charges after free time in successive day bands at increasing rates. APL, UAE import D&D notice, 2018 Not every tariff is built this way; check the structure of the one that applies to you.
Where bands do rise, they change how you should prioritise. A container just past free time costs less per day than one deep into a higher band, so the container that has been waiting longest may deserve attention first. Multiply by the number of containers before choosing which problem to fix.
No rate in this article is a current tariff. Obtain the applicable schedule from your carrier and terminal.
Delays that push a container into demurrage, and how to anticipate them
Several common causes of demurrage can be anticipated before arrival.
A document correction. An invoice, certificate or transport-document detail does not match what customs or a regulator requires. Prevent it: reconcile the full document set against the destination's requirements before the vessel sails and again before arrival. For who issues each document and in what order, see the document set behind one shipment.
A missing permit or registration. Some food and other regulated goods need an import approval before release. Prevent it: confirm the permit route with your customs broker when the order is placed, not when the vessel is at berth.
An inspection or hold. Physical inspection, sampling or a regulatory hold adds days you do not control. Prevent it: ask your broker which inspections are likely for this product and origin, book what can be booked early and build the rest into the plan.
A payment or release step. If the carrier will not release cargo until an original bill of lading is surrendered or charges are paid, a bank or courier delay becomes a terminal delay. Prevent it: know where the original bills of lading are and when they will reach the release desk. Reading a bill of lading explains the main release mechanisms.
Empty return: where detention builds after the job seems finished
Detention often builds after the importer considers the delivery complete. The goods are in the warehouse; the empty container is still in your custody.
Three conditions shorten this leg:
- Unloading capacity booked for the day the container arrives, not the next available slot.
- A return appointment at the designated depot, confirmed before gate-out where the depot uses appointments.
- The correct return location. A container returned to the wrong place may not stop the clock. Maersk's 2020 UK notice, for instance, ended import charges on the day the empty was gated in at the designated port or terminal. Maersk UK notice, 2020
In the United States, an interpretive rule of the Federal Maritime Commission (FMC) states that detention practices that do not serve their incentive purpose, such as charging when empty containers cannot be returned, are likely to be found unreasonable. That is a US standard, not a rule that applies elsewhere. eCFR, 46 CFR 545.5
Worked example: two clocks, two causes
Hypothetical teaching example. The importer, carrier, port, free time and rates are invented to show the arithmetic. They are not a tariff, a quotation or a Maqboola shipment. Amounts are in illustrative currency units (CU).
Assumptions. Two 40-foot containers of bagged rice. Separate demurrage and detention clocks, both counted in calendar days including weekends. Day 1 is the discharge day (a Thursday). Demurrage: 5 free days, then 80 CU per container per day for days 6 to 10 and 160 CU from day 11. Detention: 7 free days from gate-out (gate-out day is detention day 1), then 50 CU per container per day for days 8 to 14. Terminal storage is billed separately and is excluded.
What happened. Because two of the five free days fell on a weekend, clearance could not have finished before day 6 even with perfect documents; the realistic gate-out date was day 7. A certificate of origin wording error was then found on day 5, and the corrected original arrived by courier on day 11. The containers left the terminal on day 12. Unloading finished on detention day 3, but the depot's earliest return appointment was detention day 10.
| Clock | Charged days per container | Calculation per container (CU) | Two containers (CU) | Cause |
|---|---|---|---|---|
| Demurrage, planning gap | Days 6 and 7 | 2 × 80 = 160 | 320 | Arrival before a weekend |
| Demurrage, document error | Days 8 to 12 | 3 × 80 + 2 × 160 = 560 | 1,120 | Certificate correction |
| Detention | Detention days 8 to 10 | 3 × 50 = 150 | 300 | Depot appointment backlog |
| Total | 870 | 1,740 |
Three causes produced the bill, and only one was the document error. Asking a supplier to bear the whole 1,740 CU would overstate what the error caused; accepting the whole bill as bad luck would miss two problems you can plan for.
A carrier using one combined free-time allowance, or counting free time in working days, would produce a different result from the same events. Recalculate under the actual clause rather than transferring this answer.
Who ends up paying
Who receives the carrier's invoice depends on the carrier's tariff, the contract of carriage and local law. Who bears the cost between buyer and seller is a separate question, answered by the sale contract.
An Incoterms® rule allocates delivery, risk and specified costs between seller and buyer, but do not rely on the delivery term alone to decide who bears destination charges caused by delay; state the allocation in the sale contract. Where payment is by documentary collection and the buyer does not take up the documents, container and storage charges can keep accruing while the seller decides what to do with the goods; documentary collection or letter of credit discusses that risk.
Querying a charge: evidence and realistic expectations
A query stands or falls on records, not on frustration. Assemble:
- the tariff or contract clause and its edition or effective date;
- discharge, availability, gate-out and empty-return timestamps;
- evidence of carrier-side or terminal-side delay, such as a refused appointment or a closure;
- the invoice itself, checked against the dates above.
No outcome is guaranteed, and practice differs widely by country. Some jurisdictions regulate billing. In the United States, FMC rules require specified invoice content, issuance within 30 calendar days from the date on which the charge was last incurred, and at least 30 calendar days from the invoice date for the billed party to request mitigation, refund or waiver. eCFR, 46 CFR 541.6 to 541.8 In September 2025 a US federal appeals court set aside the separate section of that rule on whom invoices may be sent to; the FMC states that the rest of the rule remains in effect. FMC, 20 November 2025 These US rules do not govern charges at UAE or African ports. Elsewhere, work from the carrier's tariff, your contract and local law.
Common mistakes
- Planning from "standard" free time instead of the clause for this booking.
- Treating the invoice heading as the definition of the charge.
- Leaving the document check until the vessel has berthed.
- Forgetting that terminal storage may be billed separately from carrier charges.
- Assuming the job ends at delivery, while the empty sits unreturned.
Next step
When you send Maqboola a sourcing enquiry, include the destination port, your expected clearance route, any import permits the product needs and the free time in your booking or contract. Sharing these at enquiry stage lets both sides check documents and timing against the free time before shipment. Confirm free time, counting rules and rates with your carrier and terminal.
General information. This article explains common practice and cited carrier and regulatory examples for general educational purposes. It is not legal, customs or shipping advice. Free time, charges and billing rules vary by carrier, terminal, contract and jurisdiction; confirm the terms that apply to your shipment with your carrier, terminal and forwarder.
