Demurrage vs Detention: Free Time, Per Diem and Charge Examples

Quick overview

In a common ocean-import arrangement, demurrage applies when a container remains at the terminal beyond its allowed free time. Container detention concerns extended use of the carrier’s equipment outside the terminal, usually until the empty container is returned. Per diem means “per day” and can be the billing label for equipment detention.

These are starting definitions, not universal invoice rules. Some carriers use combined demurrage and detention, while terminal storage may be separate. Always check the tariff or contract for the actual charge, time period and equipment involved. FMC overview, FMC treatment of terminology and per diem.

Demurrage, detention, per diem and storage compared

The table describes common import usage. The applicable terms determine the exact start and stop events.

For a documented example of separate facility and equipment charges, see Hapag-Lloyd’s US detention and demurrage policies.

Truck waiting detention and container detention can arise on the same shipment, but they measure different services and periods. Ask your haulier to explain its waiting-time conditions separately. The drayage guide explains the port-to-inland transport stage.

This guide focuses on ocean containers. For LCL cargo, confirm the warehouse or container-freight-station storage and handling terms; the full-container empty-return example below may not describe your booking.

Demurrage and detention explained in 35 seconds

See where each charge generally applies and which deadlines, documents and operational steps can help reduce your exposure.

What is free time, and what is the last free day?

Free time is the allowance before a specified time-based charge begins. The last free day, often abbreviated LFD, is the final charge-free day under that allowance.

One shipment can have different deadlines for terminal pickup, equipment return and other services. Ask for these details in writing:

• The charge covered by the allowance.
• The event that starts counting and whether that day is included.
• Whether free days are calendar days or working days.
• How chargeable days are counted after free time expires.
• Whether pickup and return days are included.
• The treatment of holidays, closures, holds and unavailable appointments.
• The rate tiers, currency, container size/type and tariff effective date.

Do not assume weekends are always free or always chargeable. For example, Hapag-Lloyd’s US guide distinguishes free-time calculations from charging after expiry and includes specific closure provisions. Confirm the policy that applies to your booking. Hapag-Lloyd US tariff guide.

Free-time timeline: separate demurrage and detention

Hypothetical example only. This is an invented tariff and schedule for one container, not a carrier quotation or a statement of legally applicable charges.

Assumptions: all days are countable calendar days; there are no holds, closures or other exclusions. Demurrage counting starts on Day 1 with four free days, and the pickup day is included. Detention counting starts the day after pickup, with three free days, and the accepted empty-return day is included.

Delivery to the warehouse does not, by itself, establish that the empty container has been returned. Keep the return receipt or equipment interchange record showing acceptance at the instructed location.

Worked example: separate charges

Using the timeline above, assume these invented rates:

• Demurrage: $150 per day for the first two chargeable days, then $225 per day for the next tier.
• Detention: $100 per day for the two chargeable days in this example.

The subtotal excludes any separately applicable terminal storage, chassis charges, truck waiting, taxes or other services. Add a charge only if it applies to the shipment and has not already been included elsewhere.

For tiered rates, calculate each tier separately. Do not apply the highest daily rate to every day unless the actual tariff expressly uses that method.

What changes with combined demurrage and detention?

With a combined allowance, one equipment-use period can cover both time inside the terminal and time outside it. Pickup does not necessarily start a fresh free-time allowance. Terminal storage may still have a separate schedule.

A useful Spain example is Maersk’s published import guidance: it describes combined D&D from discharge through empty gate-in, invoiced as detention, and terminal storage through full gate-out, invoiced as demurrage. This is one carrier’s arrangement, not a rule for every Spanish shipment. Maersk Spain import guidance.

Hypothetical combined-charge calculation

Assume a different, invented contract for one container:

• Day 1 is the first countable day.
• Seven combined free calendar days cover the terminal and outside-terminal periods.
• The loaded container leaves the terminal on Day 5.
• Empty return is accepted on Day 12, and that day counts.
• The first three chargeable days cost €80 each; the next two cost €120 each.

Gate-out on Day 5 does not reset the clock in this example. Separate terminal storage, if applicable, must be calculated under its own terms.

The euro figures are invented for illustration. They are not Maersk’s rates, an estimate for Spain, or a currency conversion of the previous example. These examples describe alternative charging models; do not add their totals together.

Do these charges also apply to exports?

Export schedules use different events. Equipment detention can concern the period from collecting an empty container to returning it loaded, while export demurrage concerns time at the terminal before loading under the applicable tariff. Confirm the receiving window and what happens if the vessel schedule changes. Do not reuse an import timeline without changing its events. Hapag-Lloyd’s US export and import policies.

Prevention checklist

For US ocean imports, prepare the ISF filing within its required timeline. ISF acceptance does not by itself complete customs entry or terminal release.

For port collection planning, use the drayage guide. Track release and empty-return tasks as well as vessel arrival; arrival alone does not make a container ready for collection.

What if pickup or empty return is unavailable?

Report the problem promptly to the relevant carrier, terminal or haulier. Keep dated evidence of unavailable appointments, terminal closures, return instructions, rejected returns, holds and attempts to resolve the issue.

Request written instructions and a review of the affected days. Do not assume that every delay automatically earns a waiver, or that every invoice is valid simply because a tariff was cited.

For US-regulated movements, the FMC’s interpretive rule considers cargo availability and whether detention serves its purpose when empty containers cannot be returned. The facts matter; it is not a blanket waiver for all congestion. 46 CFR 545.5.

For Spain and other destinations, use the applicable local terms and dispute process. Do not apply US regulatory guidance as a worldwide rule.

How to check an invoice

Before accepting the calculation, reconcile:

1. Shipment and equipment: container number, type, size and relevant booking or bill-of-lading reference.
2. Charge description: equipment detention, demurrage, terminal storage, truck waiting or another service.
3. Applicable terms: agreed free time, tariff version and any approved extension.
4. Start and stop records: the events actually used to calculate the period.
5. Day-count rules: weekends, holidays, closures and whether event days count.
6. Rate calculation: each tier, currency, taxes and number of containers.
7. Possible duplication: whether a storage or per-diem line is already included in another charge.

Send a dispute through the stated channel within the applicable deadline, identify the specific disputed days or amounts, and attach supporting records. Keep the written response. If cargo is awaiting release, separately confirm the payment, credit or other release arrangement while the dispute is reviewed.

Plan the complete delivery and return movement

When requesting freight services, include the delivery location, unloading needs, receiving hours and intended service scope. Ask how free time, terminal collection and empty return will be coordinated.

Explore ocean freight services or US customs clearance and delivery services. Confirm the services and charges included in your booking.

Sources and further reading

• Federal Maritime Commission: detention and demurrage.
• 46 CFR 545.5: US interpretation of reasonable detention and demurrage practices.
• Hapag-Lloyd: country-specific detention and demurrage tariffs.
• Hapag-Lloyd: US tariff guide, May 2026.
• Maersk: Spain import procedures and demurrage/detention terms.