Most import cost overruns do not sit in the freight rate. They show up where the shipment changes hands: at the supplier’s dock, at the discharge port, inside customs, on the truck, and at your own receiving door. I manage import shipments into the US every day, and the same five points account for nearly every invoice that ends up larger than the quote.
1. The supplier’s dock: documents and the ISF clock
Almost everything that goes wrong downstream started as a paperwork problem here. The commercial invoice, the packing list, and the ten data elements of the Importer Security Filing all originate with the supplier, and US Customs and Border Protection must receive the ISF at least 24 hours before the container is loaded at origin. A late, missing, or inaccurate filing is a $5,000 claim per violation, and one shipment can carry more than one. First violations are often mitigated to $1,000 to $2,000 on petition, but the petition still costs you weeks.
What I ask for at booking, not at sailing: the manufacturer’s full name and address, the HTS number for every line, the container stuffing location, and a packing list whose piece count matches the invoice. A mismatch between those two documents is one of the most common hold triggers I see at the other end.
2. The discharge port: free time starts before you notice
Terminal free time at US ports typically runs four to five days, and it starts at discharge, not at customs release and not when the truck shows up. Demurrage then bills per calendar day and escalates: commonly $150 to $250 a day in the first tier, rising to $350 or more by the second week. A container that clears free time and waits six more days collects roughly $1,400 before anyone has moved it.
The gap here is ownership of the vessel ETA. Unless watching it is somebody’s named job, nobody notices the day the clock starts.
Get the discharge date and the last free day in writing, and have the trucker’s appointment booked against it.
3. Customs: classification decides the duty, the exam decides the delay
Two costs live here. The first is the duty rate itself. HTS classification sets the base rate, and for goods made in China, Section 301 adds 7.5 to 25 percent on top of it. The Merchandise Processing Fee adds 0.3464 percent of entered value, capped at $651.50 per entry in 2026. Get the classification wrong in your favor and you are exposed on every entry filed under that number. Get it wrong against yourself and you overpay every shipment until someone notices.
The second cost is time. A customs hold or exam stops the container on the terminal while the demurrage clock from point two keeps running, and the exam site charges, plus the extra drayage to and from the exam station, land on your invoice. I cannot control which containers get selected. I can control the things that invite a closer look: documents that disagree with each other, vague product descriptions such as “gifts” or “parts”, and a shipper name that differs from the one on the ISF.
4. The truck: three meters running at once
Drayage is where the small daily charges pile up. The chassis under the container rents by the calendar day, commonly $25 to $45. If the chassis and the container sit at different locations, the driver makes a separate trip to fetch the frame, billed as a split fee of $50 to $150. And once the box leaves the terminal, the carrier’s own clock starts: per-diem on the container itself, typically $100 to $200 a day after three to five free days, until the empty is returned.
At $35 a day, the difference between a two-day and an eight-day chassis cycle is $210 per container, on every container. Ask the trucker for the empty return date on every load, and check that the return terminal will accept that carrier’s equipment on that day.
Empties turned away at the gate are a per-diem bill nobody planned for.
5. Your receiving door: the last clock is yours
The delivery leg has its own meter. A driver waiting at the warehouse beyond the free window, usually one to two hours, bills hourly at $50 to $100. A missed appointment can push the container back a day, which restarts the per-diem and chassis math above. And for sellers delivering into Amazon fulfillment centers, a load that arrives without the right labels or appointment is refused, which means a second delivery and often a second day of chassis and per-diem.
This is the point importers assume they control, and it is the one they most often leave to the last minute. Dock hours, the unloading crew, and the pallet count should be settled the week before, not when the driver calls from the gate.
What this means for the number you quote your customers
Take one container that sits six days past free time and then returns four days late. It collects roughly
$1,400 in demurrage and another $400 to $800 in per-diem before a single chassis day or driver hour is counted, and none of that appears in the freight quote. That gap belongs in your landed cost before you set a price, not in a dispute after the invoice arrives.
My rule for every shipment is simple. Before it sails, each of the five points has a named owner, a date, and a number. If any of those three is blank, that is where the money will go.
About the author
Max Kershnitskii is Operations Manager at Platton, a freight forwarder for companies importing into the US. He works with importers sourcing from China, Vietnam, India, and Europe on the cost and compliance calls that shape a shipment, from HTS classification and Section 301 exposure to demurrage and per-diem control, and writes about the practical side of import logistics on Platton Insights.
