What is FCL Detention and Demurrage?

Detention and demurrage are two of the most expensive — and most misunderstood — charges in FCL ocean freight. Both bill you per container per day, both escalate after a few days, and both are entirely avoidable if you plan the unloading window carefully. This guide breaks down the difference and gives you a practical playbook.

The two charges, side by side

Demurrage

Charged by the port while the container is sitting at the terminal beyond the free time. You triggered demurrage if your container landed on Monday, you were given 5 free days, and the container is still at the port on Saturday because you did not pick it up.

Detention

Charged by the carrier after you pick the container up, for keeping their box beyond the free time before returning it empty. You triggered detention if you picked up the container Tuesday, you had 5 free days to unload and return, and you returned it the following Wednesday.

Free time — the number that matters most

Every carrier contract includes a free time window — the number of days you can keep the container without paying detention or demurrage. Free time is negotiated, not standard.

• Spot rates: usually 3–5 combined free days for detention and demurrage.
• Contract rates (mid-volume): 7–10 free days.
• BCO contracts (high volume): 10–14 free days.
• Peak season: ports sometimes reduce free time unilaterally — check before booking in October-November and February.

Per-diem rates (typical 2026 ranges)

• Days 1–3 over: USD 75–150 per container per day.
• Days 4–7 over: USD 150–250 per container per day.
• Days 8+: USD 250–450 per container per day.
• Reefer and special equipment: 2–3× the standard rate.

On a busy week at Los Angeles or Long Beach during a chassis shortage, a single 40HC stuck for ten extra days easily generates USD 2,000–3,000 in demurrage alone.

A practical example

You import 1 × 40HC of furniture to Los Angeles. Vessel discharges on a Monday. Your contract gives you 5 free demurrage days at the port and 5 free detention days at your warehouse, combined into a 7-day total.

Timeline:

• Monday — container available at the terminal.
• Wednesday — broker clears customs.
• Friday — chassis shortage; first pickup slot is the following Tuesday.
• Following Tuesday — container picked up. 8 days at the port = 1 day over = ~USD 100 demurrage.
• Wednesday–Friday — warehouse unloads, returns container Saturday. 4 detention days, but only 6 free days remain (8 + 4 = 12 vs 7 combined), so 5 days × USD 100 = ~USD 500 detention.
• Avoidable extra cost: USD 600.

How to avoid detention and demurrage

• Pre-clear customs. ISF and entry can be filed before the vessel arrives; aim to be cleared on day 1.
• Book the trucker before the vessel arrives, not the day customs releases. Chassis and driver capacity is the bottleneck, not the container.
• Negotiate combined free days on contract — a single 10- or 14-day pool is much more flexible than separate windows.
• Unload to the floor, not to the racks, then re-rack after the empty is returned. Saves 2–3 days for many warehouses.
• Have a backup yard for empties — if the carrier's empty depot is closed or full, you keep the box and the per-diem clock keeps ticking.
• Use the right container in the first place. A 40HC that arrives 60% full takes longer to plan because nobody schedules it as urgent. Match container to volume — the Container Capacity Calculator tells you whether your cartons actually need a 40HC or fit a 40ft.