Demurrage vs. Detention: What's the Difference and How Do You Avoid Fees?

1. What Demurrage and Detention Actually Are

We have seen importers receive a demurrage invoice they did not budget for. Then, a week later, a second invoice from the port authority for the same shipment. Two separate charges. Two separate parties. Most had no idea either was coming. The reason is almost always the same: they did not know the difference between demurrage, detention, and port storage before the ship arrived.

There is also a third charge that arrives separately: port storage. This is charged by the terminal or port authority, not the shipping line, for cargo occupying yard space. You can receive both a shipping line demurrage invoice and a port authority storage invoice for the same shipment. Budget for both.

2. The Clock: When It Starts and How It's Counted

Free days are not counted from when the ship arrives at port. They are counted from when your specific container is discharged and available for collection. On a large vessel, unloading can take 2 to 5 days. By the time you receive an availability notice, you may have already burned through several free days without knowing it.

Free time is also structured in two completely different ways depending on the carrier and route. Get this wrong and you can burn through your entire free window while the container is still sitting in the terminal, before you have even collected it.

"A single free-day figure on a quotation tells you almost nothing. What matters is whether it is combined or split, and exactly when the count begins."

4. The Day-by-Day Timeline

Understanding this sequence is what separates importers who pay demurrage from those who never do.

5. What It Actually Costs

Charges are not flat fees. They escalate in daily tiers the longer you hold the container. The first few days may cost $10. By week three, the same day can cost $50 or more — and every previous day is already locked in. Here is what three active M3LOGI routes cost in real terms.

To put Norway in perspective: 5 free days at $10 per day per leg means a single week's delay costs $70 in shipping line charges alone, before port storage is added. Ghana deserves a specific mention for a different reason. The shipping line's demurrage is one invoice. The Ghana Ports and Harbours Authority (GPHA) issues a separate port storage invoice at $52.50 per day for a 40ft container after the 7-day free period. Both apply to the same shipment. Importers who budget for one and not the other arrive underprepared.

The same structure applies in Kenya, Tanzania, Jamaica, and Pakistan, all major used car import destinations from Japan. In these markets, receiving only one invoice and assuming you are settled is one of the most common clearance mistakes. The second invoice arrives later, often after the car has already been collected, and by then the charges have been accruing for days.

6. RoRo vs Container: A Different Risk

Everything above applies to container shipments only. If your vehicle ships RoRo, there is no container, no demurrage clock, and no detention clock. Your only exposure is vehicle port storage if the car sits uncollected at the destination terminal. If your car runs and your route has RoRo service from Japan, use it. It removes the entire D&D risk from the equation.

For container shipments, the following seven steps are what keep the bill at zero. Most importers who pay demurrage skip at least one of them.

7. How to Avoid the Fees

Most demurrage and detention bills are avoidable. The process is not simple, and the shipping industry does not make it easy to know what you owe or when. But the importers who consistently avoid these charges follow the same discipline. They prepare before the ship departs, not after it arrives.

1. 1
   Confirm free-day structure in writing at bookingAsk three questions: How many days? Combined or split? Does the clock start at vessel arrival or discharge? Get the answers on the booking confirmation before you commit.
2. 2
   Get the Bill of Lading right the first timeOne typo in the consignee name, VIN, or port of discharge forces a correction and stalls cargo release while demurrage accumulates.
3. 3
   Appoint your clearing agent before the ship departs JapanYour agent needs the B/L, invoice, packing list, and any inspection certificates to pre-lodge the customs entry before the vessel arrives.
4. 4
   Track the vessel and plan for early arrivalsVessels frequently arrive before their ETA. Free days start counting regardless of when you expected them to. Set vessel tracking alerts.
5. 5
   Have duty, tax, and port charge funds ready before arrivalYou cannot collect cargo until all charges are paid. Cash-flow delay is one of the most common causes of demurrage.
6. 6
   Pre-book haulage and return the empty the same dayHave the trucker ready to take the empty container back to the depot immediately after unpacking. Returning the next day costs a full detention day per container.
7. 7
   Budget separately for port storageIn Ghana, Kenya, Tanzania, and Jamaica the port authority bills storage independently from the shipping line. Build both into your cost estimate before committing to a shipment.

8. Frequently Asked Questions

Disclaimer: Demurrage, detention, and port storage rates change frequently. All figures are indicative, based on quotations and carrier tariff data current at July 2026. Always confirm with your carrier at time of booking.