Unplanned demurrage and detention rarely result from one isolated mistake. An import container may remain at the terminal because the bill of lading has not been released, customs documents are incomplete, duties are not funded or the receiving warehouse is unavailable. After gate-out, costs may continue if unloading is slow or the empty container is returned to the wrong depot. For exports, collecting an empty container too early, missing cut-offs, delayed cargo readiness or rollover can consume free time before the box is loaded on board. The main control failure is monitoring only ETA and customs clearance instead of the full event chain: discharge, gate-out full, gate-in empty, pick-up empty, gate-in full and loaded on board. This guide maps the causes of unplanned D&D by operational stage and identifies the evidence needed to stop the clock.

Operational reference for importers, exporters, procurement, logistics and operations teams | Updated 16 July 2026

QUICK FACTS

When does demurrage arise?

When carrier equipment remains inside a terminal, port or depot beyond the applicable free time.

When does detention arise?

When equipment remains outside the terminal and is not returned empty or gated in full within the agreed free time.

Most common causes

Unclear free time and counting rules, document release delays, customs delays, unavailable trucks/warehouses, slow unloading and late empty return.

Critical control point

Manage each container through actual timestamps and EIR/gate evidence, not only ETA or a general “delivered” status.

Illustration for Why Businesses Incur Unplanned Demurrage and Detention Charges — Illustration of the logistics topic, document or operation discussed in the article.

SCOPE

This article covers carrier-owned containers used in FCL ocean imports and exports. Some NVOCCs and forwarders may apply equivalent terms in their service quotations. The focus is Demurrage, Detention, Combined D&D and their relationship with Storage.

Do not use this article to assume free days or rates for a specific shipment. Free time, day-counting rules, start/stop events, equipment type, tariff slabs and billed party vary by carrier, country/port, contract and booking. Reefer, DG, OOG, tank and other special equipment may have shorter free time and different rates.

TERMINOLOGY

Term	Meaning	Operational role
Free Time	The agreed period during which DEM, DET or Combined D&D is not charged.	The time budget to be confirmed before booking or arrival.
Demurrage – DEM	Charge for carrier equipment kept inside a terminal, port or depot beyond free time.	Linked to discharge/gate-in full and gate-out full/loaded-on-board events.
Detention – DET	Charge for carrier equipment kept outside a terminal, port or depot beyond free time.	Linked to import gate-out full–gate-in empty or export empty pick-up–gate-in full.
Combined D&D	Demurrage and detention merged into one continuous period.	Time saved inside may be available outside, subject to the applicable terms.
Storage	Charge for use of terminal, port or depot space beyond permitted time.	May be invoiced separately and is not automatically included in D&D.
EIR	Equipment Interchange Receipt.	Evidence of gate-out, gate-in, equipment condition and return location.
Tariff slab	A daily-rate band based on the number of excess days.	Daily cost often escalates as the container remains longer.
Calendar / Working day	Consecutive calendar days or eligible working days.	Determines whether weekends and holidays are counted.

HOW THE D&D CLOCK WORKS

D&D is tied to the use of carrier equipment beyond the agreed period. The key question is not only when customs clears the cargo, but which system event starts the clock, which event stops it and whether that event has been recorded correctly.

Direction	Charge	Typical start event	Typical stop event	Common misunderstanding
Import	Demurrage	Discharge from vessel or gate-in full at an inland depot, depending on local terms.	Gate-out full from the terminal/port.	ETA is not necessarily the start date; actual discharge may differ.
Import	Detention	Gate-out full.	Gate-in empty at the assigned depot/terminal.	Unloading completion does not stop detention.
Import	Combined D&D	Discharge/gate-in full.	Gate-in empty.	Separate DEM and DET should not be added when one combined period applies.
Export	Detention	Pick-up/gate-out empty.	Gate-in full.	Collecting the empty too early consumes free time.
Export	Demurrage	Gate-in full.	Loaded on board the designated vessel.	Missed cut-off or rollover can extend terminal time.
Export	Combined D&D	Empty pick-up.	Loaded on board.	Cancellation or schedule changes may extend the combined period.

Note: Local tariffs may count the event day differently, use calendar or working days, and apply separate or combined periods.

HOW ARE DEMURRAGE AND DETENTION CALCULATED?

Estimated D&D = Sum of each tariff slab: chargeable days in the slab × daily rate per container for that slab.

A single formula of “days late × one daily rate” may be wrong because tariffs can escalate by slab, equipment size/type and each day or part of a day may be due in full.

Required data	Verification example	Risk if missing
Free-time allocation	5 demurrage days and 4 detention days, or 9 combined days.	Duplicate charging or incorrect allocation.
Day-counting rule	Calendar/working days and event-day inclusion.	One to several days of variance around weekends or holidays.
Actual gate events	Discharge, gate-out full, gate-in empty.	Using document dates instead of system timestamps.
Tariff slabs	Days 1–3, 4–7, day 8 onward.	Applying the lowest rate to the full period.
Equipment	20’/40’ dry, reefer or special equipment.	Using a dry tariff for special equipment.
Storage/reefer services	Ground rent, power and monitoring.	Assuming DEM includes every terminal cost.

Illustrative example: if the valid tariff grants five free demurrage days and gate-out full occurs on counting day eight under that tariff, three demurrage days apply. If four detention days are free and gate-in empty occurs on counting day six, two detention days apply. The actual calculation must follow the booking-specific event-day rule.

CAUSES OF UNPLANNED DEMURRAGE AND DETENTION

Cause group	Operational symptom	Likely charge	Control point
Free time and tariff not confirmed	Quotation says only “standard free time”; no separate/combined or day-type rule.	DEM, DET or both.	Obtain written confirmation at booking/container level.
Wrong start/stop event	Team tracks ETA instead of discharge or treats unloading as the end of detention.	Charges start earlier or end later than budgeted.	Use a milestone sheet based on actual gate events.
Arrival notice or ETA change missed	Early arrival, email in spam or no weekend coverage.	Import demurrage.	Set ETA/discharge alerts and backup ownership.
B/L release or D/O delay	Original not surrendered, freight/local charges unpaid or authorization missing.	DEM and storage.	Clear release requirements before ETA.
Customs/specialised documents not ready	HS or document mismatch, missing C/O, permit, inspection registration or test result.	DEM/storage and potentially later DET.	Pre-audit documents and assign deadlines.
Duty/tax funding delay	Internal approval, credit limit or banking/system delay.	Import DEM.	Forecast duties and arrange funds before clearance.
Inspection, sampling or customs hold	Container cannot be moved pending authority action.	DEM and storage.	Plan lead time and inspection location/equipment.
No truck, terminal slot or warehouse window	Appointment unavailable, driver shortage or warehouse closed.	DEM before gate-out; DET after gate-out.	Reserve primary and backup capacity within free time.
Slow unloading	Heavy/OOG cargo, damaged pallets, counting dispute or warehouse congestion.	Import DET.	Create unloading plan by container and handling productivity.
Wrong/closed empty-return depot	Depot changed, full, appointment unavailable or equipment not accepted.	Import DET.	Confirm return instructions on the return date and retain EIR.
Empty gate-in not closed in system	Wrong container number, pending transaction or missing timestamp.	DET continues on invoice.	Check carrier tracking immediately after return.
Damage/cleaning/repair dispute	Depot rejects handover or does not close the equipment cycle.	DET plus repair/cleaning.	Photograph condition at pick-up and return.
Special equipment has stricter terms	Reefer, DG, OOG, tank or special dry differs from dry tariff.	Higher DEM/DET and faster escalation.	Use the correct equipment tariff.
Empty collected too early for export	Cargo or documents are not ready.	Export DET.	Pick up only after cargo-ready and loading plan confirmation.
Missed cut-off/VGM/SI or rollover	Full container enters terminal but misses the intended vessel.	Export DEM/combined D&D.	Control CY cut-off, SI, VGM, customs and onboard confirmation.
Booking cancelled or changed	Equipment has already been collected/gated in.	DEM/DET and shifting costs.	Issue written return/rebooking instructions immediately.
Unclear ownership	Sales, documentation, customs, trucking and warehouse wait for one another.	All unplanned D&D types.	Use a RACI and escalation before last free day.

IMPORT VS EXPORT CAUSE MAP

Stage	Import risk	Export risk	Evidence to retain
Before arrival/booking	B/L release, permits, tax and truck/warehouse plan not locked.	Cargo not ready but empty collected; unclear booking free time.	Quotation, booking and free-time statement.
At terminal	D/O/customs/inspection/appointment delay.	Early gate-in, missed SI/VGM/CY cut-off or rollover.	Arrival notice, customs status, appointment and gate EIR.
Outside terminal	Warehouse unavailable, unloading slow or consignee delays.	Loading delay or container held at factory.	Gate-out EIR and loading/unloading records.
Closing equipment cycle	Wrong return depot or missing gate-in empty event.	Booking change/cancellation or no loaded-on-board event.	Return instruction, EIR, tracking and onboard status.
Invoice reconciliation	Wrong free time, tariff, container event or duplicate storage.	Wrong pick-up/gate-in/onboard date or cancellation rule.	Invoice, tariff, event history and dispute correspondence.

DOCUMENTS AND DATA TO CHECK

Document/data	Issued/prepared by	Use	Fields to match
Quotation/Service Contract	Carrier/NVOCC/forwarder and customer.	Before booking.	Free time, separate/combined, tariff, validity, equipment and payer.
Booking Confirmation	Transport provider.	Import/export planning.	POL/POD, vessel/voyage, equipment, cut-offs and contract reference.
Arrival Notice/Discharge status	Carrier/agent/terminal.	Before and after ETA.	ETA, actual discharge, container list and location.
B/L release and D/O status	Carrier/NVOCC/agent.	Import release.	Original/surrender/sea waybill, payment holds, consignee and authorization.
Customs/specialised files	Importer/exporter, supplier and customs broker.	Clearance and inspection.	Description, HS, model, quantity, origin, permit and C/O.
Terminal appointment/Truck plan	Terminal, haulier and warehouse.	Gate-out/gate-in.	Slot, truck/driver, container and warehouse window.
EIR and gate events	Terminal/depot/carrier.	Start/stop evidence.	Container, full/empty status, timestamp, location and condition.
Empty Return Instruction	Carrier/depot.	Empty return.	Valid depot, equipment type, validity and appointment.
Invoice/Debit Note	Carrier/NVOCC/forwarder/terminal.	Cost reconciliation.	Container, period, free days, tariff slab, rate, currency and storage lines.

D&D CONTROL PROCESS BEFORE FREE TIME EXPIRES

Step	Input	Control action	Output
1. Confirm terms	Quote, contract and booking.	Confirm free time, separate/combined, day type, tariff and equipment.	Approved free-time sheet.
2. Build a container clock	Container list and event rules.	Set discharge, last free day, gate-out, empty return or onboard deadlines.	Container-level milestone dashboard.
3. Pre-clear documents	B/L, invoice, packing list, C/O, permits and duty estimate.	Audit gaps and owners before ETA/cut-off.	Ready file or timed gap list.
4. Lock field capacity	Truck, slot, warehouse, handling equipment and labour.	Reserve primary and backup resources.	Feasible gate and handling plan.
5. Monitor daily	Actual gate events and customs status.	Update variance, remaining days and escalation.	Alert before last free day.
6. Close the equipment cycle	Return instruction or onboard status.	Verify EIR, timestamp and carrier tracking.	Evidence that the clock stopped.
7. Reconcile/dispute	Invoice, tariff and event history.	Recalculate each slab and separate D&D/storage.	Accepted or corrected invoice.

BUDGETING RISKS AND COMMON ERRORS

Planning error	Impact	Control
Writing “5 free days” without identifying DEM or DET.	Different operational interpretations and budget gaps.	State DEM, DET or Combined plus event rules.
Budgeting only until customs clearance.	DET continues during unloading and empty return.	Budget through gate-in empty or loaded on board.
Not separating storage from DEM.	Understatement or duplicate cost.	Check carrier and terminal tariffs separately.
Using document dates instead of event timestamps.	Incorrect number of chargeable days.	Prioritise EIR and event history.
Ignoring holidays/weekends.	Free time expires when no operating capacity is available.	Plan against the real calendar and tariff day type.
No special-equipment contingency.	Faster escalation than dry equipment.	Check reefer/OOG/DG terms and additional free time options.
Assuming external delay is automatically waived.	Missed dispute deadline or insufficient evidence.	Review contract, local rules and submit a documented request.
No authority for urgent decisions.	Delay in buying free time, changing depot or arranging overflow capacity.	Set cost thresholds and escalation rights.

OFFICIAL SOURCES

Official source	Information used	Application limit
Maersk – Terms for Detention and Demurrage	Definitions and import/export start and stop events.	Carrier terms; booking-specific local tariffs still apply.
Hapag-Lloyd – Detention and Demurrage	Inside/outside terminal distinction and time/customs management.	Operational guidance; rates require local tariff.
CMA CGM – D&D General Terms	Import/export events, calendar/working days, chargeable day and storage separation.	Individual tariffs may provide different rules.
Hapag-Lloyd – D&D Tariffs	Country-level tariff lookup and history.	Select the correct country, direction, equipment and period.
U.S. FMC – D&D Billing Rule Status Update, 20 Nov 2025	The rule was issued on 23 Feb 2024 and took effect on 28 May 2024; on 23 Sep 2025, the court set aside only 46 C.F.R. 541.4, while the remaining provisions stayed in effect.	U.S. jurisdiction only; do not treat the invoiced-party rule in 46 C.F.R. 541.4 as still effective or as a universal legal basis.

FAQ

Does demurrage stop immediately after customs clearance?

Not necessarily. Demurrage commonly stops at gate-out full; a cleared container still inside the terminal may continue accruing.

Does detention stop when unloading is completed?

No. It usually stops when the empty container is gated in at the assigned depot/terminal and recorded in the system.

Are weekends and holidays counted?

It depends on whether the tariff uses calendar days or working days. Do not exclude them without checking.

Is storage the same as demurrage?

Not automatically. Storage relates to terminal/port/depot space and may be invoiced separately.

Can additional free time be purchased after arrival?

Some carriers offer additional free time subject to eligibility and purchase windows. Availability must be checked for the booking.

Are terminal closures or vessel delays automatically waived?

No. Waiver or dispute depends on tariff, contract, evidence and applicable local regulation.

What evidence is needed for a D&D invoice dispute?

Free-time confirmation, valid tariff, event history, EIR, release/customs records, return instruction and documented timeline.

APPLICATION NOTE: D&D is location-, contract- and time-specific. This article does not replace the booking tariff or terms. Verify free time and event history at container level; all day-count examples are illustrative only.

TGIMEX IMPLEMENTATION SUPPORT

TGIMEX helps businesses turn the article into a shipment-ready checklist, covering input-data review, dossier preparation, milestone control, and coordination with the relevant parties.

Convert guidance into checks

Assign an owner and deadline to every operational control point.

Reconcile shipment data

Compare booking, transport, commercial, customs, and delivery evidence.

Manage operational risk

Record discrepancies, actions, and decision evidence to prevent recurrence.

Discuss your shipment dossier

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