Guide · Freight
A load can be quoted correctly, covered correctly, delivered on time, and still lose money — because a facility held the truck for four hours and nobody wrote down when it arrived.
Every rate, free-time window, and dollar figure below is an illustrative example of the arithmetic, not a quote and not a market rate. Accessorial terms are set by contract and by tariff, and they vary by lane, mode, equipment, facility, and carrier. Read your own rate confirmation and your own customer contract before relying on any number here.
These three words get used interchangeably in conversation and mean quite different things on an invoice. Getting them wrong costs money in both directions — billing demurrage when you mean detention gets the invoice rejected, and quoting detention when the customer's contract says demurrage gets you a dispute.
| Term | What is actually being charged for | Where it lives |
|---|---|---|
| Detention | Holding the truck and driver at a facility beyond the agreed free time | Over-the-road trucking: shipper and receiver docks |
| Detention (per diem) | Keeping an ocean container outside the terminal, at your yard or the consignee's, beyond free days | Intermodal and drayage |
| Demurrage | Cargo or a container sitting inside the terminal or port beyond free days | Ocean and rail terminals |
| Storage | Cargo sitting in a warehouse or at a carrier's terminal after the free period | LTL terminals, warehouses |
| Layover | A driver held overnight, usually after detention has run past a cap | Trucking |
| TONU | Truck ordered, not used — the load cancelled after the truck was dispatched | Trucking |
| Accessorial | Any charge that is not linehaul: the umbrella term for all of the above and about thirty more | Everywhere |
The distinction that trips up newcomers is detention versus demurrage in intermodal. The container is a single object, but the clock that is running depends on where it is standing: inside the terminal it accrues demurrage; outside the terminal it accrues detention, also called per diem. A container that sat five days at the port and then four days at the consignee generates two different charges from two different clocks, frequently on two different invoices.
Most brokerages bill four or five accessorials regularly and lose money on the other twenty because nobody recognised them as billable events. The list is worth reading once in full.
The pattern worth noticing: almost every item on that list is an event that happened to the driver. If the only record of the trip is a rate confirmation and a proof of delivery, every one of them is invisible by the time the invoice gets built. That gap is the same structural problem described in the back-office guide — information that exists but is not queryable.
There are two separate questions here and conflating them is where brokerages lose money.
The difference between those two numbers is not a rounding error, it is your margin. The single most valuable contract-negotiation habit in a small brokerage is making the accessorial terms you owe carriers and the accessorial terms you bill customers match in shape: same free-time window, same hourly rate, same cap, same notification requirement. Every point of mismatch is a structural loss that recurs on every load through that facility.
In intermodal and ocean, the "who owes it" question is additionally a regulatory one. Recent US Federal Maritime Commission rulemaking constrains who a demurrage and detention invoice may be issued to, what the invoice must contain, and the windows for issuing and disputing it — broadly, an invoice must be issued within a set number of days of the charges last accruing, and the billed party must be given a defined window to dispute. Those specifics change; verify the current rule text rather than working from memory, and read every D&D invoice against it, because a non-compliant invoice is a disputable invoice.
Free time is contractual, not statutory. These are the shapes you will most often encounter, not entitlements.
| Situation | Typical free time | Then what |
|---|---|---|
| Dry van, live load or live unload | 2 hours | Hourly detention, often $50–$100/hr, frequently capped |
| Reefer, live load or unload | 2–3 hours | Higher hourly rate; the reefer is burning fuel while it waits |
| Flatbed | 1–2 hours | Plus tarping time billed separately |
| Drop trailer | No dwell clock on the driver | Trailer per-diem or trailer rental instead |
| Ocean container, inside the terminal | 3–5 free days (demurrage clock) | Per-container per-day, escalating in tiers |
| Ocean container, outside the terminal | 3–5 free days (detention / per diem clock) | Per-container per-day, escalating in tiers |
| Rail intermodal ramp | 24–48 hours after notification | Storage, then escalating storage |
| LTL terminal storage | Typically 1–2 days after arrival notice | Per-hundredweight-per-day storage with a minimum |
Two things about that table matter more than the numbers. First, ocean and rail clocks escalate in tiers — day six is not priced like day twelve, and a container forgotten for two weeks generates a charge that can exceed the value of what is inside it. Second, free time on containers is usually counted in calendar days at some terminals and working days at others, which is a four-figure difference across a holiday weekend and is exactly the kind of clause nobody reads until the invoice arrives.
A detention claim is a factual assertion — the truck was there from this time to that time — and it will be tested by someone who does not want to pay it. The claims that get paid have independent, contemporaneous evidence. The claims that get denied have a driver's recollection.
Aim for three independent records of the same two timestamps. Any single source can be disputed; three consistent sources effectively cannot.
Most contracts require notice before or as free time expires, not after the fact. The mechanism is deliberate: it gives the customer a chance to call the facility and fix the delay while it is still fixable. Miss the notification window and the claim is often dead regardless of how good the evidence is. This is the single highest-leverage process change available: an alert at the 90-minute mark on a two-hour clock, sent automatically, converts more detention into revenue than any amount of after-the-fact chasing.
| What kills a claim | Why | The fix |
|---|---|---|
| In and out boxes on the BOL left blank | No documentary source at all | Make signed in/out times a required field on the driver's checklist |
| Times written in by the driver days later | Not contemporaneous; trivially disputed | Capture at the moment, from the system that already has it |
| Notification sent after delivery | Contract window missed | Automatic alert before free time expires, not after |
| Rate confirmation silent on free time and rate | Nothing to bill against | Free time, hourly rate, and cap as required fields on every rate confirmation |
| Detention billed weeks later on a separate invoice | Customers reject standalone accessorial invoices routinely | Bill accessorials on the original invoice, with the evidence attached |
| Only the driver's word | One disputable source | Three sources, as above |
This is the part that is easy to underrate. Consider an illustrative load: 1,100 miles, customer rate $1,850, carrier pay $1,550. Gross margin $300, or 16.2% — a perfectly normal load.
Now the receiver holds the truck four hours past free time. The carrier's rate confirmation says two hours free then $60 per hour, so you owe four hours: $240. What you recover depends entirely on paperwork and on contract terms.
| Scenario | Owed to carrier | Recovered from customer | Net margin | Margin % |
|---|---|---|---|---|
| No detention at all | $0 | $0 | $300 | 16.2% |
| Detention documented, contract at parity ($60/hr, no cap) | −$240 | +$240 | $300 | 16.2% |
| Detention documented, customer contract caps at 2 hrs @ $50 | −$240 | +$100 | $160 | 8.6% |
| Detention paid, never billed (no timestamps) | −$240 | $0 | $60 | 3.2% |
| Detention paid, billed late and rejected | −$240 | $0 | $60 | 3.2% |
Read the last two rows again. One facility and one missing timestamp took an ordinary 16.2% load down to 3.2% — and the load still looks fine in a report that only tracks linehaul revenue against carrier pay. This is why unbilled accessorials are described as a silent leak: they do not show up as a loss anywhere, they show up as margin that was never there.
Same load. The receiver requires a lumper, the driver pays $185 out of pocket, you reimburse the carrier, and the charge does not make it onto the customer invoice because the receipt arrived as a photo in a text message three days later. That is $185 off a $300 margin, or off the $160 that survived the detention above — at which point the load has cost you money to move.
Per load these are small numbers. The reason they matter is that they are a percentage, and percentages compound across volume. Illustratively, at 200 loads a month with an average gross margin of $300, monthly gross margin is $60,000.
| Unbilled accessorial leak | Monthly cost | Annual cost | Equivalent to |
|---|---|---|---|
| 2% | $1,200 | $14,400 | A meaningful software budget |
| 4% | $2,400 | $28,800 | Most of a junior back-office salary |
| 6% | $3,600 | $43,200 | A full hire, unfunded |
| 10% | $6,000 | $72,000 | A materially different business |
Nobody knows their own number, which is the actual problem. The way to find it is not an estimate — it is a month of deliberately logging every accessorial event (not charge) as it happens, then comparing that log against what was actually invoiced. The gap between the two is the leak, and it is almost always larger than the guess.
Most of that is document matching, timestamp capture, deadline watching, and invoice assembly — structured, repetitive, deadline-driven work, which is precisely the category that automates cleanly. That is what FreightDesk is built to do: pull the accessorial evidence that already exists in the email and event stream onto the invoice before it goes out, and raise the exceptions to a human. The detention, margin, and rate-per-mile calculators are free on the freight tools page, and the arithmetic underneath them is worked through in the margin guide.
One last connection worth making: the carrier who bills you an accessorial you cannot verify, and the carrier who should never have been on the load in the first place, are frequently the same conversation. The carrier vetting checklist covers the front half of that problem.
FAQ
Detention in trucking is a charge for holding the truck and driver at a facility beyond the agreed free time. Demurrage is a charge for cargo or a container sitting inside a terminal or port beyond the free days. In intermodal the same container generates demurrage while it is inside the terminal and detention, also called per diem, once it is outside.
Two hours is the common shape for a dry van live load or unload, two to three for reefer, and one to two for flatbed, after which detention is billed hourly and often capped. Ocean containers typically get three to five free days on each clock, and rail ramps commonly 24 to 48 hours after notification. All of these are contractual, not statutory, so the rate confirmation governs.
Two separate questions. The broker owes the carrier whatever the signed rate confirmation states, and bills the customer whatever the customer contract or tariff allows. The gap between those two numbers comes out of the broker's margin, which is why matching the free-time window, hourly rate, cap, and notice requirement across both contracts matters more than negotiating the rate itself.
Aim for three independent, contemporaneous sources of the same two timestamps: an ELD or GPS geofence arrival and departure event, in and out times signed on the bill of lading by facility staff, and a timestamped check call or app event logged at arrival. Any single source can be disputed; three consistent sources effectively cannot.
Most often because notice was not given before free time expired, since most contracts require notification while the delay is still fixable rather than after the fact. The other common causes are blank in and out boxes on the bill of lading, times written in by the driver days later, a rate confirmation that never stated free time or a rate, and accessorials billed weeks later on a standalone invoice.
Lumper fees paid out of pocket by the driver, driver assist, pallet exchange, layover after a capped detention, stop-off charges, reconsignment and redelivery, tarping, liftgate and residential delivery, limited-access locations, and after-hours delivery. Almost all of them are events that happened to the driver, so they are invisible by invoicing time unless something captured them when they occurred.
Illustratively, at 200 loads a month and an average gross margin of $300, a 4% unbilled leak is $2,400 a month and $28,800 a year, which is most of a junior back-office salary. The honest answer is that nobody knows their own number, and the only way to find it is to log every accessorial event for a month and compare that log against what was actually invoiced.
Yes, easily. On an illustrative load with $300 of gross margin, four hours of detention owed to the carrier at $60 an hour is $240. Recover it in full and the margin is unchanged; recover nothing because the timestamps were never captured and the same load falls to $60, or 3.2% — and it still looks fine in any report that only tracks linehaul against carrier pay.