In October a lighting seller in Shenzhen shipped a 40HQ to Los Angeles on DDP terms, delivered to a third-party warehouse in Ontario, California. Customs released the container on the 3rd. The warehouse had its first free dock slot on the 10th. Seven days of container time arrived as an invoice at month end, made out to the party that had booked the space — the seller.
Nothing in that story is unusual, and that is the point. A DDP quote is built on normal turnover: discharge, clearance, a few days inside the carrier's free time, delivery. Waiting sits outside that model, so it never appears on the quote.
Two charges, two different clocks
People call both of them "demurrage" and then argue about the bill. They are separate clocks, and they do not start at the same moment.
| Charge | When the clock runs | What it looks like on a DDP file |
|---|---|---|
| Demurrage | After free time ends, while the box is still inside the terminal | Nobody collected it: no appointment, no release, no truck |
| Detention | From gate-out to gate-in, past the free days | The box went out and did not come back: queue at the warehouse, no dock, no forklift |
| Free time | Usually four to seven days from discharge, set by the carrier rather than the forwarder | The one number that turns a fixed quote into an open one |
Why the invoice reaches the seller
Demurrage and detention are billed to whoever holds the contract with the carrier. Under DDP the seller books the space, so the carrier bills the seller's forwarder and the forwarder bills the seller. The buyer never sees the charge: the buyer paid a door price and, as far as the buyer knows, the door price covered everything.
Here is the counter-intuitive part. DDP hands the seller the risk of import clearance, and with it the risk of everything at destination that is measured in days. A DDP quote that does not say how many container days are included is not a fixed price. It is a price with an open end.
Three things that eat the free time
- The warehouse calendar. In peak season a west coast warehouse may be booking inbound docks a week out. Delivery is "arranged"; the appointment is what blocks it.
- An exam at clearance. A customs hold does not extend free time. The box sits, the clock runs, and the customs broker has no power to stop either.
- No way to unload. A receiver without a dock leveller, a forklift or staff that day cannot empty a 40HQ and return it before the free days end. Detention starts when the return is late, not when the unloading is finished.
Give it a line in landed cost
Treat it like duty or the broker fee: one line of its own. Before quoting, ask the forwarder for two figures — the free days at the destination terminal, and the daily rate after that, per box size. Then write the line into the offer in plain words: includes delivery within N days of release; beyond that, container time is billed at cost with the carrier statement attached.
Sellers who do this stop absorbing the charge quietly. Sellers who do not usually meet it the first time a buyer asks for a Friday delivery and the warehouse opens on Tuesday.
Five things the desk does before booking
- Ask for the free-time figure in writing, per carrier and per port, and file it with the booking.
- Take the release timestamp from the customs broker on the day, not at month end.
- Lock the warehouse appointment before the vessel sails, not after it berths.
- Name a backup receiver that can take a 40HQ at two days' notice.
- Put the excess-day sentence into the offer and into the supplier's purchase order.
The file that settles the argument
- Release timestamp from the customs broker, and any exam notice.
- Gate-out and gate-in records for the container.
- The warehouse appointment confirmation, with the date it was first requested.
- The carrier's demurrage and detention statement, broken down by day and by box.
A plain note from the desk: freight rates are renegotiated every week; waiting time is never negotiated until the invoice arrives. The cheapest protection is one sentence in the quote and one appointment booked early.
If you are quoting DDP from Shenzhen to the USA and want the waiting days priced before the buyer asks, send the lane, the box size and the receiver's address on WhatsApp. We will come back with the free time, the daily rate and a delivery window in one message.