A detention invoice rarely shows up when you expect it. The container moved, the cargo got where it needed to go, and weeks later a per-container, per-day bill lands on your desk for time nobody was tracking. Unlike demurrage — which is largely a function of how fast customs and documentation move — detention is the one carrier charge you control almost entirely yourself. That also means it's the one with no good excuse for recurring.
What actually triggers a detention charge
Detention is a carrier charge for keeping a container outside the terminal beyond the carrier's free return window. The clock starts the moment you take custody of the equipment — usually at gate-out for an import pickup, or at empty drop-off for an export stuffing — and it keeps running until the empty box is physically back inside the terminal gate. It has nothing to do with the port, customs, or the vessel; it's purely about how long you keep the carrier's equipment.
Free time for detention is set by the carrier, not the terminal, and it commonly runs 3–7 calendar days depending on the trade lane and the equipment type. Once that window closes, detention accrues in tiers — a modest daily rate for the first bracket, stepping up the longer the box stays out. A container held two weeks past free time can rack up charges well beyond what the ocean freight itself cost on a short-haul lane.
The free-time clock, at a glance
| What starts the clock | Gate-out (import pickup) or empty drop-off (export stuffing) |
|---|---|
| What stops the clock | Empty container physically gated in at the terminal |
| Typical free time | 3–7 calendar days (carrier and lane specific — always confirm) |
| Day counting | Most carriers count calendar days, including weekends and holidays |
| Rate structure | Tiered — daily rate increases the longer the box is held |
Because the clock counts calendar days, a container picked up on a Friday afternoon can burn through half its free time before a single business day of trucking is even possible. That single fact is behind more detention invoices than any other.
Build the return plan before the container arrives
The single biggest lever against detention is timing the trucking booking to the vessel, not to the container's arrival. Waiting until a box is sitting at the terminal to start arranging drayage guarantees you lose days of free time to scheduling alone.
Practical steps to put in place before the vessel berths:
- Book drayage as soon as the vessel ETA is confirmed, not after discharge
- Confirm the destination terminal's gate hours and any cut-off times for empty returns
- Reserve a slot for both the loaded pickup and the empty return in the same booking where the trucker allows it
- Check whether the destination city has truck curfews or restricted zones that limit which hours a container can move
- Flag reefer or special-cargo units for priority handling — a genset failure or plug delay eats into the same free-time window
For FCL ocean freight, the container is a single unit moving on a single clock, so a missed trucking slot on day one is rarely recoverable inside a 3–7 day window without deliberate buffer.
Where the clock actually gets away from you
Most detention charges trace back to one of a handful of recurring failure points. Knowing which one applies to your operation tells you where to fix the process.
| Cause | What happens | Fix |
|---|---|---|
| Driver or truck shortage | No capacity available to move the box on short notice | Book drayage against the vessel ETA, not the discharge date |
| Warehouse congestion | Container sits stuffed or unstripped waiting for dock space | Schedule stripping/stuffing slots before the container arrives |
| Gate cut-off missed | Truck arrives after the terminal's return window closes | Confirm gate hours in advance; build in a buffer for traffic |
| Weekend or holiday | Clock keeps running but no trucking or gate access is available | Front-load pickup/return earlier in the free-time window |
| Extended dwell for sorting | Cargo held at the warehouse for consolidation or inspection | Separate the "cargo processing" timeline from the "return equipment" timeline |
The pattern across all five is the same: detention is a logistics execution problem, not a documentation problem. Fixing it means treating the empty return as its own scheduled task, not an afterthought once the cargo is unloaded.
Coordinate the handoffs, not just the truck
A container's free-time window touches more than one party — the trucker, the warehouse crew, and sometimes a road freight partner handling the inland leg. Detention slips through the cracks when those parties aren't working off the same date.
- Share the carrier's free-time expiry date with everyone touching the container, not just the trucker
- On exports, coordinate the stuffing schedule with the empty pickup window so the box doesn't sit at your dock before you're ready for it
- If a shipment involves multiple pickups or a transload, confirm which leg's completion actually stops the detention clock
- Keep one point of contact tracking the date rather than relying on the trucking company to flag it — a missed alert is the most common reason free time expires unnoticed
Ask for an extension before the clock runs out, not after
Carriers will sometimes grant a short extension on free time — for a documented warehouse delay, a genuine trucking capacity shortage in the market, or a special-cargo handling issue. The window for that conversation is before the free days expire. Once detention has already started accruing, most carriers treat a waiver request as an exception rather than a routine courtesy, and it's a harder case to make.
If you know in advance that a shipment will need more time — a reefer unit going through cold treatment, an oversized load needing specialised trucking — flag it with the carrier or your forwarder as early as possible rather than waiting to see if the return happens on schedule.
If a detention invoice still arrives
First, verify the dates against your own gate-out and gate-in timestamps — carriers do miscalculate start dates and rate tiers. Second, check whether the delay falls under a carrier-caused exception, such as equipment they were supposed to swap but didn't, or a documented terminal outage that blocked returns. Third, dispute promptly — most carriers only accept detention disputes within a short window after the invoice is issued, so treat it with the same urgency as any other deadline-driven cost.
How Holo Cargo helps
Booking through Holo puts drayage, container milestones, and the carrier's free-time window in one place, so nobody is tracking the return date from memory or a separate spreadsheet. Our operations team coordinates the empty-return booking against the vessel schedule from the start, and flags shipments approaching their free-time expiry before the clock runs out rather than after. Seeing how a shipment moves end-to-end makes it easier to see exactly where the return window sits in the process — and where the risk actually is.
