Demurrage and detention: what they cost, who owes them, and how to fight them
A shipper-side guide to the two charges carriers publish tariffs for and nobody explains: how free time is calculated, real per-container-per-day rates, who is legally liable, and the evidence that wins a dispute.
What demurrage is, and what it isn't
Demurrage is the daily charge an ocean carrier applies when your loaded container stays inside the port or terminal longer than the free time your contract allows. Detention is the daily charge for keeping the container outside the terminal, on your yard or at your dock, past free time. Both are billed per container, per day, and both escalate.
The complexity is not in the definition. It is in the clock: when it starts, what stops it, which calendar it counts, and who is deemed responsible for the days in between.
The purpose of the charge matters, because it is the basis of every successful dispute. Demurrage and detention are not rent. They are not a revenue line the carrier is entitled to for storage services rendered. They exist to push equipment back into circulation. A carrier owns a finite pool of boxes and chassis, a terminal owns a finite number of ground slots, and both need the asset back. The charge is a penalty designed to make sitting still more expensive than moving.
This is why the charge is vulnerable when the cargo could not have moved. If the terminal was closed, the appointment system had no slots, the container was buried under four others, or the return depot turned your driver away, then the charge is not incentivizing anything. It is just a bill. Hold that thought. It is the argument that recovers money when you get to the dispute section below.
One warning on the word itself. In bulk and charter shipping, demurrage means the daily amount a charterer pays a vessel owner for exceeding agreed laytime, at a rate fixed in the charter party — same word, different contract, usually five figures a day rather than three. If your document says laytime and despatch, you are in that world, not this one. Everything below is containerized demurrage.
Demurrage vs detention vs storage: three charges, one container
The difference in one line: demurrage is what you pay while the container is still sitting inside the terminal past its free time. Detention is what you pay once you have taken the container out and kept it too long before returning the empty. Same box, same carrier, two clocks — one running inside the gate, one outside it.
The most expensive misunderstanding in this category is treating demurrage and detention as two names for the same thing. At many gateways there is also a third charge: the terminal operator bills storage or quay rent under its own schedule, on its own free-time clock, because it is a different company with a different contract. A carrier demurrage invoice and a terminal storage invoice covering overlapping days on one container can both be valid. Read both schedules before you assume you were double-billed.
One container, three possible meters: carrier demurrage (inside the gate), terminal storage or quay rent (inside the gate, different contract), and carrier detention or per diem (outside the gate).
| Charge | Where the box is | Who bills it | Clock runs | Typical free time |
|---|---|---|---|---|
| Demurrage (import) | Inside the terminal | Ocean carrier, per published tariff | Container available after discharge → out-gate | 3-5 calendar days |
| Terminal storage / quay rent | Inside the terminal | Marine terminal operator | Discharge or expiry of terminal free time → out-gate | 0-4 days, often shorter than the carrier's |
| Detention / per diem (import) | Outside, in your possession | Ocean carrier | Out-gate with the loaded box → empty returned and receipted (EIR) | 3-5 calendar days |
| Detention (export) | Outside, in your possession | Ocean carrier | Empty pickup from depot → full container gated in | 3-7 calendar days |
| Demurrage (export) | Inside the terminal | Carrier or terminal | Gate-in before the receiving window, or after a roll → loaded to vessel | Receiving window, commonly ~7 days pre-cutoff |
How free time actually works: the clock nobody is watching
Free time is not a grace period you negotiate at the moment of the problem. It is a fixed count of days that starts without asking you, and the last free day is knowable weeks before it arrives. Almost every avoidable demurrage invoice traces to the same root cause: nobody calculated the last free day, so nobody knew there was a deadline.
The first input is the availability date. Depending on the tariff that is the date of vessel discharge completion, the date the container is available for pickup, or the date of the arrival notice — and on a big discharge those can differ by two or three days. Check which one your carrier's tariff names, because the difference is worth hundreds of dollars a box. The second is the number of free days, from your rate agreement if you negotiated one, otherwise from the carrier's default tariff for that trade and port. Contract and spot free time are frequently different, and reefer free time is almost never the same as dry.
The third input is the one that catches people: the calendar convention. Some tariffs count calendar days, weekends and public holidays included. Some count working days. Four calendar days on a container discharged the Thursday before a long weekend can leave one working day to clear customs and arrange drayage. Four working days on the same box gives you a week. Same number in the contract, completely different operational reality.
Last free day = availability date + contracted free days
Calendar days unless the tariff explicitly says working days. Calculate it the day the vessel berths, not the day the invoice lands.
Then there is the list of things that do not stop the clock, which is the list that generates the invoices. A customs examination does not stop demurrage. A missing or incorrect commercial invoice does not stop it. No available drayage appointment does not stop it. A chassis shortage does not stop it. A container buried in the stack does not stop it. A return depot refusing your empty does not stop detention. Some of these are disputable after the fact. None of them pause the meter while they are happening.
If your boxes move inland on rail, run the same exercise for the ramp, because the numbers are worse there. Free time at an inland rail terminal is frequently shorter than at the discharge port, storage is billed by the railroad under its own tariff rather than by the ocean carrier, and per diem keeps running on the carrier's clock the entire time the container is in rail transit. An IPI move to a Midwest ramp can burn most of the detention allowance before the box is ever available to your drayman.
One container · two meters
What the clock actually looks like
Seeded with one 40HC dry container at a major US West Coast gateway: 4 calendar days of demurrage free time, 5 of detention, on one carrier's tier structure. Bar height is the daily rate, so the staircase is the escalation. Illustrative, built on one published tariff structure — pull your own carrier's and the shape stays, the numbers move.
Three containers in this position is $9,900. That arithmetic is below.
Nobody made a bad decision. The boxes landed, an exam held four of them, and the free-time clock kept running on all twelve while the paperwork moved. The arithmetic is further down this page.
What it costs: per container, per day, by tier
Tariffs are tiered and the tiers escalate steeply, because the point is to make the box hurt more the longer it sits. A typical structure runs days 1-5 past free time at one rate, days 6-10 at roughly 1.5 to 2 times that, and day 11 onward at 2.5 to 3 times. The bands below are what you will find across major carrier tariffs at large gateways. They are bands, not quotes — they were dramatically higher at US West Coast ports during the 2021-2022 congestion peak than in a normal market. Pull your own carrier's published tariff for the port in question; that document is the only rate that holds up in a dispute.
| Equipment | What drives the rate | Tier 1 (days 1-5) | Tier 2 (days 6-10) | Tier 3 (day 11+) |
|---|---|---|---|---|
| Demurrage, dry 20ft | Port class; mid-size gateways at the low end | $75-$150 / day | $150-$250 / day | $250-$400 / day |
| Demurrage, dry 40ft / 40HC | Port class; major US and NW European gateways at the high end | $150-$275 / day | $250-$400 / day | $400-$650 / day |
| Demurrage, reefer | Plus plug-in, monitoring and genset charges billed separately | $250-$450 / day | $400-$700 / day | $700-$1,200 / day |
| Demurrage, special equipment (flat rack, open top) | Availability of the equipment type at that terminal | $150-$300 / day | $300-$500 / day | $500-$800 / day |
| Detention / per diem, dry | Generally billed below demurrage on the same box | $75-$175 / day | $150-$300 / day | $250-$450 / day |
One thing to get right before you use these numbers: free time is set by the port, the trade lane and your contract — not by container size. A 20ft and a 40HC discharged off the same vessel get the same allowance under almost every tariff. What size changes is the rate, and even then plenty of US tariffs bill a flat amount per container regardless of size while others step up for 40ft and above. Check which yours does before you build a model.
The escalation also has an operational consequence most teams miss. Triage by tier position, not by age. A box on day 9 costs you materially less tomorrow than a box on day 10 does, because tomorrow the second one crosses into a new tier. With limited drayage on a given morning, you move the container about to escalate, not the oldest one.
Reefers are their own category: shorter free time, higher daily rates, and separate plug-in, monitoring and genset charges layered on top, which is why a reefer in a customs hold accrues faster than anything else on the terminal.
Worked example: twelve containers, one customs exam, $9,900
Twelve 40HC dry containers arrive on one vessel at a major US West Coast gateway. Your rate agreement gives 4 calendar days of demurrage free time and 5 of detention. The tariff bands are $200 per day for demurrage days 1-5, $325 for days 6-10, $500 from day 11; detention is $150 per day for days 1-5, $250 from day 6.
Nine boxes clear and move inside free time. Cost: zero. Three are pulled for a customs examination that runs nine days past the last free day. Those three then gate out, drayage that week is tight, and the return depot has no empty-return appointments for your carrier's equipment — so the empties sit six days past the five free detention days.
Twenty-five percent of the containers on that vessel generated 100% of the cost, and the blended cost across the whole twelve-box shipment is $825 per container.
Demurrage owed = Σ (days in tier × tier rate) × containers
Tier escalation means the marginal day is always more expensive than the average day.
4,000
Containers / yr
6%
Incident rate
$1,400
Avg charge
$336,000
A year
A shipper moving 4,000 import containers a year with a 6% incident rate and an average charge of $1,400 per affected box is spending $336,000 a year on demurrage and detention. That number rarely appears anywhere as a line item. It arrives as hundreds of small invoices absorbed into freight cost, or rebilled by a forwarder inside a consolidated statement, which is precisely why it goes unmanaged for years.
Who actually owes the charge
This is where shippers lose arguments they should win, because two separate systems of liability are in play and people confuse them. The first is the contract of carriage: the carrier bills whoever it has a contractual or legal relationship with — the party named on the bill of lading, the consignee, or the NVOCC that booked the space. In the United States, the Federal Maritime Commission billing rule that took effect in May 2024 tightened this significantly. The billing party must be the vessel-operating carrier, the NVOCC or the marine terminal operator that holds that relationship, and it may bill only one party for a given charge. It cannot invoice you and your forwarder for the same days and collect twice, and it cannot invoice a party it has no relationship with, such as a trucker who merely handled the container.
The second system is your commercial terms with the counterparty, which the carrier is not a party to and does not care about. Under FOB the buyer arranges carriage and destination demurrage is the buyer's problem. Under DAP or DDP the seller carries it to the named place. Under CIF the seller pays freight to the destination port but the buyer typically owns everything from discharge onward — which is why CIF imports generate so many surprise invoices for buyers who thought they had bought a delivered price.
The practical rule: Incoterms decide who ultimately absorbs the cost, the bill of lading decides who gets invoiced, and those are often different parties. If you are the consignee and the charge was caused by the shipper's late documents, you will still receive the invoice. You pay it or you accrue more, and you recover it commercially afterward.
Build that recovery mechanism into your purchase terms before you need it, in three enforceable parts: a documentary deadline naming the full set — invoice, packing list, bill of lading, certificates — in the broker's hands five working days before vessel arrival; a clause making the supplier liable for demurrage, detention and storage caused by late, missing or defective documents, evidenced by the carrier invoice and the entry timeline; and a stated remedy, normally a debit note against open payables rather than a request for a credit. Most charges blamed on ports are caused by paperwork that arrived after the vessel, and a supplier who holds the relationship will only absorb them if the deduction is automatic.
Who gets invoiced
The contract of carriage
The party named on the bill of lading, the consignee, or the NVOCC that booked the space. Under the US billing rule, one party per charge — never both you and your forwarder for the same days.
Who absorbs the cost
Your Incoterms
When you never see the carrier's invoice: the forwarder rebill
Most mid-market importers never receive a demurrage invoice. They receive a forwarder's consolidated statement, forty to sixty days after the fact, with a line reading D&D and a number. No container list, no dates, no tariff rule, occasionally a handling percentage on top.
That is not a billing convenience. It is the quiet loss of every right described in the next section. You cannot audit an invoice you have never seen, and by the time the statement reaches you the dispute window on the underlying carrier invoice may already have closed.
Three fixes, all contractual rather than operational.
Require the source document
Write into the forwarder agreement that any demurrage, detention or storage pass-through arrives with the originating carrier or terminal invoice attached, at cost, within a set number of days of the charge accruing. No source document, no rebill.
The rule follows the charge
On US trades an NVOCC that bills you for demurrage is itself a billing party under the FMC rule, and its invoice carries the same thirteen-element and thirty-day requirements as the carrier's. A statement line reading D&D $4,200 meets none of them.
Split the cost line
Get demurrage, detention and terminal storage out of freight in the general ledger and onto their own code. Until the number has a home in the P&L, nobody owns it, and a charge nobody owns is a charge nobody disputes.
An invoice is a claim, not a verdict
Demurrage invoices arrive weeks after the event, from a system that does not know what happened in your yard, and they are routinely wrong in ways that favour the issuer. The free-time start date is the most common error: it is set from a gate or discharge event that may not match the one your contract names.
None of which means the charge is illegitimate. It means the number needs checking before it is paid, and that checking it is a normal part of the job rather than an escalation. What follows is how to do that without turning every invoice into a fight.
How to dispute demurrage charges
Disputes are winnable, and they are lost far more often on evidence and timing than on merit. Treat it as a documentation exercise, not an argument.
On US imports and exports you have real regulatory leverage: the Ocean Shipping Reform Act of 2022 shifted the burden of proof so the party issuing the invoice must establish that the charge is reasonable, and the FMC billing rule then set hard requirements on the invoice itself. Outside US trades there is no equivalent regulator — in the EU, UK and Asia the case is purely contractual, so the evidence work is identical but the appeal route is your rate agreement and your annual volume rather than a regulation.
Under the US rule the invoice must be issued within 30 calendar days of the date the charge last accrued, and must carry thirteen specified data elements. You then have at least 30 days to request mitigation, refund or waiver, and the billing party has 30 days to resolve it.
Audit the invoice before you argue the facts
Issued more than 30 days after the charge last accrued, or missing any of these, on a US trade:
A missing element makes the invoice defective. You are not obligated to pay a defective invoice.
01
The timestamped rejection
A photo or gate record showing your driver was turned away from the empty return depot, with date, time and location. The strongest single document in this category. Instruct drayage partners to capture it by default and send it same-day — it is worthless retrieved three weeks later.
02
The appointment system record
Screenshots showing no available slots for the relevant days, with a visible date. Take them at the time; the board looks different next week.
03
The official hold notice
A customs examination notice, an FDA or other agency hold, or a terminal congestion advisory establishes cause and timing independently of anything you assert.
04
The equipment interchange receipt
The EIR or gate receipt fixes the exact moment detention stopped. Carriers bill from their own system record, which is sometimes days later than the physical return.
05
The terminal's own container history
Availability date, appointment availability and out-gate timestamp, pulled from the terminal website rather than from the carrier that issued the invoice.
Usually wins
– Terminal closure or strike
– Appointment unavailability
– Empty return refusal
– Chassis unavailability where the carrier controls the pool
– A container the terminal could not produce
– A vessel or booking the carrier rolled
– Any invoice that is late or missing a required element
Usually loses
– Your entry was filed late
– Your documents were wrong or incomplete
– You had no drayage arranged
– You had nowhere to unload
– You were waiting on payment or a customer instruction
Those in the right-hand column are your operational failures and the charge is doing exactly what it was designed to do. When a properly filed dispute is ignored or refused without reasoning, the escalation route for US charges is the FMC charge complaint process, which can order refunds. Most cases never get there, because most carriers will settle a well-documented file rather than defend it.
Every hour you win back is won upstream of the terminal
By the time a demurrage invoice exists, the money is already spent. The only place this cost is actually controllable is in the days before the box grounds — when the vessel schedule slips, when the customs entry is still unfiled, when the drayage appointment has not been booked.
That is why the playbook below is mostly about detection and ownership rather than negotiation. A container nobody is watching becomes a container nobody moves.
How to avoid it: the operator's playbook
Ordered by how much money each one actually saves.
1. Calculate the last free day the day the vessel berths
Put it on a screen someone looks at. You cannot manage a deadline you have not written down, and every item below is easier once the date exists.
2. Pre-clear before arrival
In the US, entry can be filed in advance of arrival and the ISF is due 24 hours before loading. Complete, accurate documents in the broker's hands before the vessel berths eliminate the largest controllable cause of import demurrage. Chasing a packing list while the meter runs is a choice you made three weeks earlier.
3. Negotiate combined free time into the annual agreement, not into the crisis
Seven to ten days of combined demurrage and detention free time is achievable at contract volume on many trades. It is often cheaper to buy free time than a lower ocean rate, because free time protects the tail risk that actually costs money. Reefer free time is harder to move. Ask anyway.
4. Book drayage against the last free day, not the arrival date
At appointment-driven gateways capacity has to be reserved days ahead. A truck ordered on the last free day is a truck ordered too late.
5. Solve the empty return before you pull the box
Return locations, per-carrier and per-equipment restrictions, and depot capacity change weekly at large ports. Detention accrues on containers nobody will take back. Confirm the return point is open to your carrier's equipment before the loaded box leaves the terminal.
6. Use street turns where the carrier permits them
Matching an inbound empty directly to an outbound booking removes a depot round trip, kills the return-refusal risk, and stops detention and export free time in one move.
7. Triage by tier, not by age
Peak season is the case that makes this necessary: forty boxes land in one week, drayage evaporates, and the whole batch hits last free day on the same day. When capacity is short, move the container crossing a tier boundary tomorrow, not the oldest one. If you arrived here with boxes already accruing, that is the first move — rank everything past last free day by tomorrow's marginal cost, pull anything reefer or special-equipment first, and open a dispute file on the ones you could not have moved.
8. Audit every invoice, not a sample
Against the tariff rate, the calendar convention and, in US trades, the required invoice elements. Teams that start auditing systematically almost always find the same two things: charges billed at the wrong tier, and charges billed for days the terminal was shut. If more than a third of your first twenty invoices turn out to be caused by someone else, you have a recoverable pool large enough to justify staffing the audit rather than squeezing it between other jobs.
9. Give it an owner and a code
In most shippers this charge is an orphan. The broker assumes logistics owns it, logistics assumes the broker does, and finance codes it into freight and moves on. Put demurrage, detention and storage on their own GL line, name one person accountable for the monthly number, accrue against open containers so the quarter is forecastable rather than arriving two months late, and report it next to freight cost per unit. The month-end conversation where a finance lead asks what the sixty thousand dollars in other freight was is not an accounting problem. It is the symptom of a cost with no owner.
Monday-morning version: pick your last twenty demurrage invoices, rebuild the clock on each one from source documents, and sort them into caused-by-us and caused-by-them. That single exercise tells you whether you have a detection problem, a documents problem, or a dispute-discipline problem — and each has a different fix.
Why this is a detection problem before it is a negotiation problem
Look back at the worked example. The $9,900 was not caused by the customs exam. Exams happen. It was caused by the fact that nobody knew the clock had started until the invoice arrived, by which point the only remaining option was to argue about days already spent.
Free time is one of the few deadlines in this business that is fully knowable weeks ahead of time, and one of the least often written down anywhere. The availability date, the tariff free days, the calendar convention, the out-gate timestamp, the empty return receipt: all of it exists, in carrier feeds, terminal portals, broker systems and your ERP. It just does not exist in one place, on a clock, with a name against it. So the box lands on Thursday, the arrival notice gets read on Monday, and two of four free days are gone before anyone has made a decision.
That is what Orkestra is for, and it is worth being exact about how. Orkestra is a layer over the ERP, TMS and WMS you already run — no rip and replace. You load the free-time terms once, per carrier and per lane, the way they sit in your rate agreement, including whether that tariff counts calendar days or working days. Orkestra then takes the availability and gate events off the carrier and terminal feeds and runs the clock against them, so shipment visibility tells you which containers are inside two days of last free day rather than just where the vessel is.
On top of that, exception management and the Exception Monitoring Agent watch that threshold continuously and surface the box while there is still free time left to book the drayage, chase the entry, or confirm the return depot will take the empty. That is the entire intervention. Not a better invoice — an earlier decision. It is the same pattern behind OTIF improvement, where the signal also existed in time to act and nobody owned the response.
The one published result worth putting next to this is OIA Global, a 4PL running a multi-client operation on Orkestra, which cut exception resolution time 60%. Whether any of that maps to your demurrage number depends entirely on how many of your charges are detection failures rather than documents failures — which is exactly what the twenty-invoice exercise above tells you before you talk to anybody, including us.
The boundary
To be exact about the boundary. Orkestra does not clear your customs entries, dispatch your trucks, or file your disputes, and it will not negotiate free time into your carrier contract. It also does not capture the two documents that win most disputes — the driver's timestamped turn-away at the return depot, and the dated screenshot of an empty appointment board. Those still come from your drayage partner, though the document module gives them one place to land against the container instead of an inbox nobody searches in March. What Orkestra holds is the timeline: availability, last free day, out-gate, empty return, and who was told what and when. That is what turns a dispute from a memory exercise into a file. The trucks, the broker and the argument with the carrier are still yours.
