Few line items sting like a demurrage or detention bill that arrives after the cargo has already moved. They're not part of the freight rate, they're not always quoted upfront, and they escalate fast. Understanding the difference — and why each one happens — is the first step to keeping them off your invoice.
What is demurrage?
Demurrage is a charge levied by the carrier when a loaded container stays inside the port or terminal beyond the carrier's free days. It's the terminal's way of pricing out congestion: if your cargo isn't collected and the box stays in the yard, you pay a daily fee until it leaves.
Free time at destination typically runs from the moment the vessel is discharged — often 3–7 calendar days depending on the carrier, the port, and the trade lane. After that window closes, demurrage begins. Rates are tiered: the first bracket might be a modest daily fee per container, escalating to a higher tier after another few days, and higher still beyond that. The longer the box sits, the steeper the per-day rate.
Demurrage applies to both import and export movements. On exports, if your container is gated in to the terminal but the booking is rolled or the vessel is delayed and you can't retrieve the box, the carrier may still charge for the time beyond their free window.
Common triggers:
- Customs holds and exam orders (your cargo can't be released while under examination)
- Slow document turnaround — arrival notice received late, B/L release delayed
- Importer not ready to collect (warehouse full, labour shortage, delayed trucking)
- Port congestion causing a backlog at the customs desk
What is detention?
Detention is a charge for keeping the carrier's equipment — the empty container — outside the terminal beyond the carrier's free return period. Once you pick up the loaded box, the clock starts. When the carrier's free days for return expire and you still haven't brought the empty back, you're in detention.
Free time for detention is similarly carrier-specific and typically starts from gate-out at the terminal. A shipper on the export side faces the mirror image: the carrier delivers an empty container to your stuffing location, and if you haven't stuffed it and returned it to the terminal gate within the free window, detention accrues.
Detention is entirely outside the port fence — it's about the box in transit, at your warehouse, or sitting at a consignee's dock. You control it more directly than demurrage, which is why carriers treat it as a separate charge.
Common triggers:
- Extended stuffing or stripping time at the warehouse
- Truck or driver availability issues preventing timely empty return
- Congestion at the terminal gate causing queued trucks to miss the cut-off
- Shipper or consignee requesting extended dwell time to sort goods
How free days, combined free time, and split free time work
| Demurrage free time (typical) | 3–7 calendar days from vessel discharge (varies by carrier and port) |
|---|---|
| Detention free time (typical) | 3–7 calendar days from gate-out of loaded container (varies by carrier) |
| Combined free time | A single shared pool of days that covers both demurrage and detention together |
| Split free time | Separate counters for demurrage and detention; each has its own clock |
| Weekend / holiday counting | Most carriers count calendar days, not business days — always confirm |
Whether a carrier uses combined or split free time matters a lot in practice. Under combined free time, every day the loaded container spends inside the terminal eats into the same pool of days you'd otherwise use for the return of the empty. Move fast in the port, and you have more buffer at the warehouse — and vice versa.
Always read the carrier's tariff or ask your freight forwarder to confirm the free-time structure before the shipment arrives.
Demurrage vs detention: key differences at a glance
| Demurrage | Detention | |
|---|---|---|
| Where it accrues | Inside the port / terminal | Outside the terminal |
| What triggers it | Loaded box not picked up in time | Empty container not returned in time |
| Who controls it most | Customs speed, document readiness | Truck scheduling, warehouse capacity |
| Charged by | Carrier (sometimes terminal adds storage separately) | Carrier |
| Escalation | Tiered daily rates, rising over time | Tiered daily rates, rising over time |
Storage (STG) is a related but separate charge — levied by the terminal operator (not the carrier) for physical yard space. It can run in parallel with demurrage. On an itemised ocean FCL quote from Holo, storage and terminal handling (THC) appear as their own destination line items so you can see exactly what each party is charging.
Why these charges escalate so fast
The tiered structure is deliberate. Carriers want their equipment back and terminals want their yard space. The first tier is priced as a nudge; subsequent tiers are priced as a penalty. A container sitting for ten days can accumulate charges multiples of what the freight itself cost on a short trade lane.
The practical problem for importers is that customs holds — the single biggest trigger of demurrage — are often outside your direct control. An examination order from customs means the cargo physically cannot leave the terminal, and the demurrage clock runs regardless. That's why fast, accurate customs documentation is not an administrative nicety; it's a cost-control lever.
How to avoid demurrage
Get your documents right, early. The arrival notice, bill of lading release, and customs entry should all be in order before the vessel berths — not after. On LCL shipments this is even more critical because you're working within a consolidated shipment's release window.
Practical steps:
- Confirm telex release or original B/L surrender well before vessel ETA
- Pre-file customs entry so that clearance can complete within the free-time window
- Use a customs brokerage partner who works on the destination side — faster document handling directly reduces port dwell time
- Build in buffer: if the carrier gives 5 free days and port clearance typically takes 3, you have no room for a customs query
- Monitor vessel ETA updates; a vessel arriving early can compress your preparation window significantly
How to avoid detention
Plan the trucking before the cargo arrives. Empty return is a logistics execution problem — it requires a confirmed drayage booking, a driver, and an open terminal gate slot.
Practical steps:
- Book drayage as soon as the vessel is confirmed, not after arrival
- Confirm empty return hours and gate cut-off times at the destination terminal
- Don't let the empty sit at your warehouse while you sort the next shipment — return it promptly and request another booking if you need a box again
- On exports, co-ordinate the stuffing schedule with the empty pickup window so the container doesn't arrive before your warehouse is ready
- If you anticipate needing more time, contact the carrier early — extensions are sometimes granted before the clock runs out, but rarely after
What to do if you receive a demurrage or detention invoice
First, verify the dates. Carriers sometimes miscalculate free time, apply the wrong start date, or use the wrong rate tier. Get the gate-in/gate-out timestamps from the terminal and compare them against the carrier's tariff.
Second, check for force majeure exceptions. If the charge accrued during a customs examination, port shutdown, or carrier-caused vessel delay (rolled cargo, vessel skip), those are grounds for a dispute or waiver request. Document everything — examination orders, terminal advisories, correspondence.
Third, act quickly. Disputes submitted months after the fact are rarely successful. Most carriers have a short dispute window.
How Holo Cargo reduces your exposure
When you book FCL ocean freight through Holo, the quote breaks down origin, freight, and destination charges separately — including terminal handling and storage where applicable. You see the cost structure before you commit, not after the container arrives.
Our operations team flags vessels with tight free-time windows and coordinates with our customs brokerage partners to keep clearance on track. Drayage scheduling on the destination side is handled proactively, not reactively. The goal is to get your equipment returned and your demurrage clock stopped as fast as possible.
Understanding how a shipment moves end-to-end helps you see where the handoffs happen and where time is lost. Getting that right is the single best demurrage and detention mitigation there is.
