Demurrage is a fee charged by the steamship line when an import container sits at the port terminal past the free time (typically 4-7 days from vessel discharge). Daily rates start around $150-$300/day for the first tier and escalate to $300-$500+/day after extended dwell.

What is per diem in shipping?

Per diem is a fee charged by the steamship line for empty containers held outside the terminal past the free return window (typically 4-5 days from pickup). It's essentially a "container rental" charge that ticks daily until the empty is returned to a designated terminal.

What's the difference between demurrage and detention?

Demurrage applies inside the port (full container sitting at the terminal). Detention applies outside the port (chassis or container held at warehouse beyond free time). Demurrage is charged by the steamship line; detention is charged by the chassis pool or motor carrier.

How can I avoid demurrage and per diem charges?

Pre-clear customs before vessel arrival, schedule pickup the day after discharge, choose carriers with good terminal performance (faster turn times), use a same-day-return drayage broker, and select warehouses with extended receiving hours. Working with an experienced drayage broker who tracks free time clocks proactively eliminates 80% of these charges.

Who pays demurrage — the shipper, broker, or warehouse?

Contractually, demurrage is the importer's/shipper's responsibility (per the bill of lading). Brokers and warehouses pass it through. However, when delays are caused by terminal congestion, vessel changes, or customs holds outside the shipper's control, demurrage may be waived or split — your broker should advocate for waivers when appropriate.

Demurrage and Per Diem Charges Explained

April 24, 2026 6 min read

What is the difference between demurrage and per diem?

Demurrage and per diem are two different container-delay charges with two different owners. Demurrage is charged by the ocean terminal when a loaded container sits at the port beyond the allotted free time. Per diem is charged by the steamship line when an empty (or loaded) container is held off-terminal — at a warehouse or chassis pool — beyond the contracted free days. Both clocks start at different events. BlackBridge Logistics tracks demurrage and per diem windows on every drayage move. Contact BBL to learn more.

How are demurrage and per diem different from detention?

Detention is a third container charge with a third owner. Demurrage is paid to the ocean terminal for time at the port. Per diem is paid to the steamship line for time the container is held off-terminal. Detention is paid to the chassis provider or the trucking carrier when equipment is held at a consignee beyond the free wait window — typically two hours for live-unloads. All three charges can stack on a single delayed container. BlackBridge Logistics flags free-time risk on every drayage quote.

How can shippers avoid demurrage and per diem charges?

Shippers can avoid demurrage and per diem charges by pre-pulling containers before free time expires, using drop-and-hook delivery to avoid live-unload bottlenecks, scheduling delivery appointments before container availability, and tracking free-time windows in real time. Working with a drayage broker like BlackBridge Logistics helps because the broker monitors LFD (last free day) on every container and dispatches pre-pulls automatically when warehouse appointments are not available. Avoiding even one demurrage day can save $150-$450 per container. Request a BBL drayage quote.

Demurrage and per diem are the two charges that blindside importers more than any others. You clear customs, the container’s ready, and then a chassis shortage or a receiving delay adds four figures to your landed cost before the container even leaves the port. Worse, the charges come from different parties — the ocean carrier, the chassis pool, the drayage provider — so reconciling them takes real work.

BlackBridge Logistics handles pre-pulls, terminal appointments, and 24/7 dispatch to keep demurrage and per diem off our customers’ invoices. This guide covers the difference between demurrage, per diem, and detention, how free days work, what typical daily rates look like, and the operational moves that actually prevent these charges.

Demurrage, per diem, detention — three different charges

These terms get used interchangeably and it creates real confusion on invoices. They’re three different charges from three different parties:

Demurrage: Charged by the ocean carrier when a loaded import container sits at the marine terminal past the last free day. Billed per container, per day.
Per diem (container): Charged by the ocean carrier when the empty container isn’t returned to the terminal or depot within the allowed free time after discharge. Billed per container, per day.
Detention: Charged by the drayage carrier when the driver waits at the shipper or receiver beyond the allotted free time (typically 1-2 hours). Billed per hour.

Demurrage and per diem are tariff-based charges owed to the ocean carrier. Detention is an operational charge owed to the trucker. All three can appear on a single move gone sideways.

How free days work

Every import container comes with free days written into the ocean carrier’s tariff or contract. Typical free day structures look like this:

Demurrage free days: Usually 3-5 calendar days from vessel discharge, sometimes longer under NVOCC contracts. The clock starts when the container becomes available at the terminal, not when it discharges.
Per diem free days: Typically 3-5 days to return the empty after the container leaves the terminal. Some contracts bundle “combined” free days that cover both demurrage and per diem on one clock.

Free days vary by carrier, service contract, and shipment type. NVOCC and beneficial cargo owner contracts frequently negotiate extended free time. Always check the actual free day count for the specific booking — don’t assume.

How charges accumulate

Both demurrage and per diem are tiered. The first few days past free time are charged at one rate, then the rate steps up. A typical tier structure:

Days 1-5 past free: $100-200 per day
Days 6-10 past free: $200-300 per day
Days 11+ past free: $300-350+ per day

These are market-typical ranges. Actual carrier tariffs vary. A container sitting 10 days past last free day on demurrage alone can easily accumulate $2,000-3,000 in charges. If per diem stacks on top because the empty return is also delayed, you’re looking at another round of charges.

What triggers extra charges

The common events that drive demurrage and per diem past free days:

CBP exam holds: Customs exam (VACIS, tailgate, intensive). Holds can last 3-10+ days depending on exam type and CES availability. Free days keep ticking while the container is in exam.
Chassis shortages: Can’t pull the container because there’s no chassis. Covered in our port drayage fees breakdown.
Terminal appointment gaps: Can’t get a pickup slot within free days. Common during peak season at congested terminals.
Vessel bunching: Multiple vessels discharge in a tight window, overwhelming terminal capacity.
Consignee receiving delays: Plant closed, appointment slot slipped, no unloading labor available. Extends the time the empty is out, triggering per diem.
Empty return restrictions: Ocean carrier limits which terminals accept the empty. If the nearest approved return yard is full, drivers get turned away and the clock keeps running.

How to actually avoid them

There’s no magic fix, but there are operational moves that reliably keep these charges off invoices:

Pre-pull strategically: When free days are tight and the receiver isn’t ready, pre-pulling the container to a drayage yard stops demurrage. Pre-pull costs a yard storage fee per day, which is almost always cheaper than tier-two demurrage.
Book appointments early: At appointment-based terminals (most major ports now), pulling a slot the day the container is available — not two days later — matters.
Monitor vessel ETA and LFD daily: Last free day is not a date to discover on day seven. Real-time tracking of vessel arrival, discharge, and free-day clock is standard operational practice.
24/7 dispatch: Empties get returned on the first available appointment, including nights and weekends when terminals accept returns. Waiting until Monday morning can cost two days of per diem.
Fast consignee turn: Schedule unload appointments tight to the pickup. The longer the empty sits at the DC, the more per diem accrues.
Hold at bonded warehouse when needed: If the plant isn’t ready, bonded storage can stop the per diem clock on the import and let inventory stage until it’s needed. See our bonded warehouse drayage page.

Exam holds — the hardest one to plan for

CBP exams are non-negotiable. The container is out of your control once it’s flagged. But there are things that still help: get the container moved to a Centralized Examination Station (CES) quickly if required, stay on top of the exam broker for status, and document the hold dates carefully for demurrage dispute later. Some carriers will waive demurrage accrued during documented exam holds if you file the dispute with proof.

Avoid demurrage with a drayage partner that’s actually paying attention

BlackBridge Logistics tracks every import container against its last free day, pre-pulls when needed, and runs 24/7 dispatch to keep empties moving. We arrange container moves out of every major US port through independent motor carriers. Call (516) 252-3395 or visit our drayage services page to get a quote.