Detention & demurrage, decoded.
Two charges that sound similar, mean different things, and quietly destroy margins. A field guide to free time, over-time, and the documentation that wins disputes.
Here's a question that has cost the global industry billions of dollars: is detention a charge for the container or for the chassis? Most ops people couldn't answer cleanly, which is why the FMC keeps fining carriers for unreasonable charges, why importers keep paying invoices they shouldn't, and why the smartest forwarders run a meticulous documentation regime on every move.
This article is the version of the lecture you wish you'd had before your first big invoice.
The basic vocabulary
Two charges, two locations, two clocks.
"You left it at the terminal too long."
Charged by the carrier when a full container sits at the marine terminal past the agreed free time. Begins ticking from container discharge; stops when the container clears the gate.
"You kept the container off-terminal too long."
Charged by the carrier when their container is held by you off-terminal past the free time. Begins ticking from gate-out; stops when the empty container is returned to the depot.
If your box is sitting at the port: demurrage. If your box is sitting at your warehouse: detention. Same carrier, same container, different charge regime.
How "free time" actually works
Every B/L (bill of lading) has free time terms embedded. Typical numbers for a North American import:
- Demurrage free time: 4–7 calendar days from discharge
- Detention free time: 3–5 business days from gate-out
- Combined free time: Some carriers (especially on contracts) bundle both into a single window — say "10 days from discharge to empty return"
Free time varies by carrier, trade lane, contract terms, container type (dry vs. reefer vs. specialised), and seasonal congestion. Reefer free time is often shorter. Special equipment free time is often shorter still.
The escalating rate schedule
Once free time expires, the per-day rate steps up. A typical schedule:
- Days 1–5 over: $100–$200/day
- Days 6–10 over: $200–$400/day
- Days 11+: $400–$800/day
These numbers explode for reefer (typically 2-3× the dry rate) and for premium terminal handling. A reefer that misses pickup at LA/LB by 14 days during peak season can easily generate $8,000 in combined charges.
Why charges show up that shouldn't
Three common failure modes:
1. The clock starts before you can act
Demurrage often begins on discharge, but if customs holds the container for a 24-hour exam, you can't move it. Most carriers will not automatically pause the clock — you have to dispute and prove the hold caused the delay.
2. Trucker no-shows
The truck didn't arrive. The carrier doesn't care why. Detention accrues from the moment the empty could have been returned.
3. Returns refused at the depot
You arrive at the empty return depot and they're full. They turn you away. Detention keeps accruing. This is the most disputed charge in the industry — the carrier owes you that depot capacity. The fact that you tried to return and were refused is your strongest disputable evidence.
Take photos at every gate event.
Gate-in receipt at terminal. Gate-out receipt at trucker pickup. Refusal slip if a depot turns you away. Time-stamped. These are the artifacts you need when the carrier invoices for charges you don't owe.
How to fight charges
The FMC (Federal Maritime Commission in the US, equivalent regulators elsewhere) requires carriers to charge reasonable rates and to provide clear visibility into how charges are calculated. As of the 2022 final rule, carriers must:
- Include specific minimum information on every detention/demurrage invoice (container number, dates, rate basis, etc.)
- Provide a clear dispute process
- Not charge for periods when the cargo couldn't reasonably be moved
If a carrier's invoice doesn't meet the minimum information requirement, it's not collectible. Yes, really.
The winning dispute toolkit:
- Tracking timeline — every event with timestamp, from discharge to empty return
- Customs notice — if customs held the box, the official notice with dates
- Depot refusal slip — if returns were refused, the dated/signed refusal
- Trucker dispatch log — proves attempted pickup/return
- Comparison with carrier's published free-time terms — what they actually contracted for
What systems can do
The single highest-leverage thing a tracking system does for D&D is start the clock visibly the moment discharge happens. Most charges accumulate because nobody noticed the container was discharged on Saturday at 11pm and the free time had already burned through by Monday morning.
A good tracking system surfaces:
- Discharge event timestamp (start of demurrage clock)
- Configurable per-carrier free-time window
- "Days remaining" countdown for every container
- Auto-alert at 1 day, 12 hours, and 0 hours of remaining free time
- Gate-out event (end of demurrage, start of detention)
- Empty return event (end of detention)
In Broadpath, every tracked container shows a "free time remaining" badge based on the carrier's standard terms. Override per-shipment if your contract is different.
The deeper play
D&D charges are not the carrier's main source of revenue. They are, however, the place where margin leaks happen for shippers and where reputational damage happens for carriers. Both sides have an incentive to get this right — and increasingly, regulators are forcing transparency.
If you're moving more than a few containers a month, your D&D spend is probably 2–5% of your freight bill. Most of that is recoverable if you have the documentation. Most teams don't.
Disputed an invoice and need an event timeline pulled from our records? Email [email protected] with the container number.