Drayage invoice charges are hard to read because a single container generates bills from four different parties, and none of them can see the others’ invoices. The ocean carrier bills demurrage and container per diem. The marine terminal bills terminal and exam-related fees. The chassis provider or pool bills chassis rental and per diem. The drayage trucker bills the move itself plus waiting time, pre-pulls, splits, and storage in its own yard. Every one of those charges references the same container number and overlapping dates, so a legitimate stack and a double bill look identical until you rebuild the container’s timeline.
That is the job. Not memorizing fee names, though the table below covers the common ones. Building one timeline per container, assigning each charge to the asset and the party it actually prices, then testing whether that party had the right to bill it at all.
Drayage also happens to be the one place in domestic freight where part of the billing process is federally regulated in detail. Ocean demurrage and detention invoices have to meet content and timing rules. The trucker’s accessorials do not. Knowing which half of your stack sits on which side of that line tells you which argument to make.
The four parties on one container
Before the charge names, get the ownership straight. Each charge prices somebody holding something, and the holder changes as the container moves.
The ocean carrier owns the box. It cares about how long the box sits inside the terminal (demurrage) and how long you keep it outside the terminal after pickup (container detention, usually called per diem on the street). Its free time is granted in the ocean contract or tariff.
The marine terminal operator owns the yard. It bills for gate moves, exams, reefer plug-ins, and in some ports its own demurrage or storage separate from the ocean carrier’s.
The chassis provider owns the chassis, which in most US ports is a different company from the ocean carrier. A pool or a leasing company bills daily rental for as long as the chassis is out, whether or not a container is on it.
The drayage carrier owns the truck and the driver’s hours. It bills the move, plus anything that consumed time or equipment beyond the move: waiting at the gate, a second trip, storing the loaded box in its yard overnight.
Four owners means four clocks, and the clocks do not start or stop together. A container can be out of the terminal (demurrage stops), still on a pool chassis (chassis per diem runs), sitting at your dock unloaded (container per diem runs until the empty is returned). All three of those days are real and all three are billable. What is not billable is the same day of the same asset billed by two parties, which is the single most common finding in drayage audit.
The fee stack, port to door
Read this as a map of who to ask, not as a list of charges to refuse. Most of these are legitimate most of the time.
| Charge | Billed by | What it actually prices | First thing to check |
|---|---|---|---|
| Ocean freight and BAF | Ocean carrier or NVOCC | The water move and bunker cost | Against the booking, not the invoice |
| Terminal handling / wharfage | Terminal or ocean carrier | Moving the box across the terminal | Whether it is already inside an all-in rate |
| Demurrage | Ocean carrier (sometimes terminal) | Days the box sat inside the terminal past free time | Last free day versus the actual gate-out timestamp |
| Container per diem / detention | Ocean carrier | Days you held the box outside the terminal past free time | Empty return receipt date, not the day you unloaded |
| Chassis rental | Chassis pool, leasing company, or trucker | Daily use of the chassis | Whether the trucker already rebilled it as a markup |
| Chassis per diem | Pool or ocean carrier | Chassis held past its own free time | Is this the same chassis-day as the rental line |
| Pre-pull | Drayage carrier | Pulling the box early and holding it in the trucker’s yard | Whether it prevented demurrage or just created yard storage |
| Yard storage | Drayage carrier | Days the box sat in the trucker’s yard | Who asked for the pre-pull |
| Chassis split | Drayage carrier | A separate trip to get a chassis from another location | Did the trip happen, and whose choice was it |
| Waiting time / detention at terminal | Drayage carrier | Driver hours burned in the gate queue | Time-stamped in and out, same as any detention claim |
| Detention at your dock | Drayage carrier | Driver hours burned at the delivery | Free time in the drayage agreement, not the ocean contract |
| Dry run / TONU | Drayage carrier | A dispatched trip that could not be completed | Who caused the failure and what the rate agreement says |
| Congestion or port fee | Terminal, ocean carrier, or trucker | Local surcharge, often published | Effective date and whether it applies to your port |
| Overweight / triaxle | Drayage carrier | Special chassis or permitting for heavy boxes | Actual scale weight against the threshold |
| Reefer plug / genset | Terminal, trucker | Powering a temperature-controlled box | Plug-in and unplug timestamps |
| Exam fees (VACIS, intensive) | Terminal, exam site, trucker | A government-ordered inspection and the moves it requires | The exam notice, and that each move is billed once |
| Hazmat | Drayage carrier | Placarding, routing, and handling restrictions | Whether the commodity actually required it |
| Fuel surcharge | Drayage carrier | Diesel cost above a base | The published index and peg in your agreement |
Two structural notes about the table. First, the same word means different things in different rows: “detention” is an ocean-carrier charge for holding the box and a trucker charge for holding the driver, and they are billed by different companies on different clocks. Second, several rows can be legitimately rebilled. A trucker who pays a chassis pool and passes the cost through is not double billing, but you should be able to see the underlying pool invoice.
The part that is actually regulated
The Federal Maritime Commission’s billing rule at 46 CFR part 541 governs demurrage and detention invoices in ocean shipping. It sets what those invoices must contain, who may be billed, when they must be issued, and how long you have to dispute them. Nothing comparable exists for a drayage trucker’s accessorials.
Three provisions do most of the work.
Timing. Under 46 CFR 541.7, the billing party must issue a demurrage or detention invoice within 30 calendar days from the date the charge was last incurred. A per diem invoice that shows up four months after the empty went back has a timing problem before you argue about the days.
Contents. 46 CFR 541.6 requires the invoice to state the defined timeframes during which you may request mitigation, refund or waiver and within which the billing party will resolve the request. The full required-contents list, twenty fields covering the shipment identifiers, the dates, the rate, and the basis for the charge, is published in the GovInfo text of section 541.6. A demurrage invoice that gives you a container number and a dollar amount is not a compliant invoice.
Your response window. Under 46 CFR 541.8, you get 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, unless you both agree to longer.
One caution, because this rule gets oversold. The text at 46 CFR 541.5 says that failing to include required minimum information “eliminates any obligation of the billed party to pay” the charge. That is strong language and it is worth quoting in a dispute. It is not a self-executing refund. Nobody credits your account automatically because a field was missing. You still have to raise it, in writing, inside the window, and be ready to escalate. Write the dispute as a demand grounded in the rule, not as an announcement that the charge has already vanished.
Also note the scope. Part 541 reaches demurrage and detention billing in ocean shipping. It does not govern what your drayage trucker charges for a chassis split, a pre-pull, or waiting time at the gate. Those are contract questions, decided by your drayage agreement and whatever rules tariff it incorporates, exactly like an accessorial on a domestic LTL invoice.
Where the same day gets billed twice
The overlap problem deserves its own method, because it is where the money is.
Build a single timeline for the container with five events: vessel discharge, last free day, gate-out, empty return, and chassis return. Then lay every invoice line against it.
- Demurrage after gate-out. The box left the terminal; terminal-side demurrage stops. Any demurrage day after the gate-out timestamp is wrong on its face.
- Container per diem before gate-out. Street time cannot begin before the box hit the street. Per diem days that predate gate-out are the mirror image of the same error.
- Chassis billed twice. The pool bills the chassis directly and the trucker also passes through a chassis line. One of them is a markup and one is a duplicate. Ask for the underlying pool invoice.
- Pre-pull plus demurrage. A pre-pull exists to beat the last free day. If you paid a pre-pull and still got demurrage for the same days, one of the two is wrong.
- Yard storage that nobody ordered. If the trucker pre-pulled for its own dispatch convenience and then billed you storage, that is a conversation about who benefited.
The full method for separating container per diem, chassis per diem, and demurrage on one box, including how to read the gate transaction records, is in auditing chassis per diem and split charges on drayage. If the same charge simply arrives twice under different invoice numbers, that is a different problem with a different fix, covered in how to detect duplicate freight invoices.
The trucker’s time-based charges
Waiting time at the terminal gate and detention at your dock are the drayage charges most likely to be both real and unprovable. Port queues are genuinely brutal and drivers genuinely lose hours in them. That is a cost somebody has to carry.
But the evidence standard is the same one you apply to a dry van detention claim. You need an arrival time, a departure time, and a source for each that is not the invoice itself. Terminal gate systems produce in and out transactions. Telematics produce geofence crossings. Your own guard log produces a third record. When the charge is at your dock, the documents that decide a detention dispute are the same list you would pull for a truckload move.
Watch two drayage-specific wrinkles.
First, free time on a drayage move is defined in the drayage agreement, not the ocean contract, and it is often shorter than the two hours common in truckload. Know which number governs before you argue about minutes. If you are unsure when the clock is supposed to start at all, the general rule and its exceptions are in when detention free time actually starts.
Second, waiting at the terminal and detention at the receiver are different charges for different waits, and a driver who burns three hours at the gate and one hour at your dock should generate two lines, not one merged four-hour line. A merged line is not fraud, it is usually a dispatcher rounding up on a busy afternoon, but it is not auditable and you can say so.
The per-container audit checklist
Run this once per container. Fifteen minutes if the records are decent.
- Assemble the timeline. Vessel discharge, last free day, gate-out, empty return, chassis return, with a source document for each date.
- Sort every invoice line by owner. Ocean carrier, terminal, chassis provider, trucker. Four buckets.
- Test each day against the timeline. No demurrage after gate-out, no per diem before it, no chassis day without a chassis out.
- Check the ocean invoices for compliance. Issued within 30 days of the last day the charge was incurred, containing the required fields, stating your mitigation window.
- Check the trucker’s lines against the drayage agreement. Rate, free time, fuel peg, and whether each accessorial is named at all. The mechanics of that comparison are the same as reconciling a rate confirmation against a carrier invoice.
- Isolate the pass-throughs. Any line where the trucker paid someone else should have an underlying invoice you can see.
- Dispute in writing, inside the window, and pay the undisputed balance. Partial payment removes the past-due leverage while the dispute runs.
- Log what you find by charge code. The value of drayage audit is not any single container, it is spotting that one terminal generates chassis split charges on 40 percent of moves while another generates none.
Step eight is where drayage differs from domestic truckload. The individual amounts are small enough to wave through and the volume is high enough that a systematic error costs real money before anyone notices. The deadlines that bound all of this, ocean-side and domestic, are collected in the freight billing deadlines reference.
What to ask for, in order
When a drayage invoice does not reconcile, ask in this sequence. It escalates naturally and each step is cheap.
First, the gate records. In and out transactions for the container and the chassis, with timestamps. Most disputes end here because the timestamps either support the charge or destroy it.
Second, the underlying invoice for any pass-through line. A chassis charge the trucker paid a pool for should be traceable to a pool invoice with the same dates.
Third, the tariff or agreement provision the charge is billed under, in its effective version. For an ocean demurrage or detention charge, also ask for the required invoice contents if they are missing, citing the rule.
Fourth, a corrected invoice with a specific deadline, and a statement of what you are releasing for payment in the meantime.
Most of what comes back will be a process artifact rather than an attempt to overbill. Ports generate messy data, four companies bill off partial views of the same container, and dispatchers reconstruct events from memory. Say that in the email. You will get corrections faster from a carrier who thinks you are fixing a data problem together than from one who thinks you are accusing them of something.
Sources
- 46 CFR part 541, Demurrage and detention billing requirements and practices (Cornell LII)
- 46 CFR 541.5, effect of omitting required invoice information (Cornell LII)
- 46 CFR 541.6, required contents of a demurrage or detention invoice (Cornell LII)
- 46 CFR 541.6 full required-contents list (GovInfo)
- 46 CFR 541.7, 30-day invoice issuance deadline (Cornell LII)
- 46 CFR 541.8, mitigation, refund and waiver request windows (Cornell LII)