A shipment may sail as planned yet still incur demurrage or detention when the importer tracks only ETA and leaves free time, cargo release, customs readiness, specialized controls, trucking, warehouse capacity and empty return arrangements unresolved. Charges usually result from a chain of dependencies: late documents delay the declaration; a late declaration misses the truck slot; a missed slot keeps the container inside the terminal or causes a late empty return. This article sets out ten pre-ETA controls, their required outputs, owners and warning signals so that free time is managed shipment by shipment rather than after charges have started.

B2B logistics operational guidance | Updated: 20 July 2026

QUICK FACTS

LOCK THE RIGHT FREE TIME

Identify separate DEM/DET or Combined D&D, start and end triggers, calendar or working days, and shipment-specific conditions.

LOCK THE CONTAINER EXIT PATH

Customs clearance alone is insufficient; D/O or eDO, trucking, warehouse slot and empty-return depot must also be ready.

LOCK DOCUMENT STATUS

Invoice, Packing List, B/L, C/O, permits and declaration data should be customs-ready before ETA.

LOCK OWNER AND DEADLINE

Each control needs one accountable owner, a completion date and a fallback.

TRACK AFTER GATE-OUT

DEM risk may end at gate-out, while DET risk continues until the empty container is accepted by the designated depot.

SCOPE

This article primarily applies to import full-container-load ocean shipments using carrier-owned containers delivered through a port, ICD or terminal. It is intended for importers, trade compliance teams, forwarders, customs brokers, trucking providers and receiving warehouses.

It should not be copied unchanged to shipper-owned containers, LCL, breakbulk, airfreight or jurisdictions with special local rules. The booking, bill of lading, carrier tariff and shipment-specific free-time confirmation take priority.

TERMS

Term	Operational meaning	Control point
ETA	Estimated Time of Arrival of the vessel at destination.	ETA may change; track vessel arrival, discharge and container availability separately.
Free Time	The agreed period during which DEM, DET, Combined D&D or Storage, if applicable, is not payable.	Confirm against the current booking; do not reuse the previous shipment’s allowance.
Demurrage	Compensation for holding the carrier’s container inside a terminal, port or depot beyond free time; it does not automatically include Storage.	The start may be tied to discharge, availability or another local trigger.
Detention	Charge or compensation when the carrier’s container remains outside the terminal/depot beyond free time.	Track from gate-out until a valid empty-return acceptance.
Combined D&D	One combined free-time pool covering time inside and outside the terminal.	Early gate-out does not create extra free days if the same combined clock continues.
Storage	Charge for terminal, port or yard space; it may be separate from DEM.	Do not assume free DEM automatically means free Storage.
D/O or eDO	Delivery Order or Electronic Delivery Order authorizing cargo/container release.	Confirm release conditions, outstanding charges and B/L surrender status.
Gate-out / Empty return	The full container exits the terminal / the empty container is accepted at the depot.	These events close the DEM and DET cycles respectively.

HOW DEMURRAGE AND DETENTION ARISE

DEM and DET primarily compensate for holding carrier equipment beyond the agreed free time, while Storage relates to the use of port, terminal or depot space and may be invoiced separately. Maersk defines free time as the period during which Demurrage, Detention, Combined D&D and Storage, if applicable, are not payable. CMA CGM describes import demurrage as the period from discharge until full-container gate-out. Actual calculation still varies by carrier, country, terminal, equipment and contract.

Importers should therefore lock four layers: charge type, start trigger, end trigger and day-count convention. Only then should customs, trucking, unloading and empty return be planned.

CONTROL NOTE: ETA is only an estimate. DEM may start from discharge, availability or another tariff event, not automatically from ETA.

10 ITEMS TO LOCK BEFORE ETA

No.	Item	Data to confirm	Required output	Risk if unresolved
01	ETA, discharge and availability	Vessel/voyage, latest ETA, POD, terminal, expected discharge and availability.	A dated timeline, data source and named monitor.	Trucking and customs plan use stale ETA; discharged containers are not acted upon.
02	Free-time structure	Separate DEM/DET or Combined; days; calendar/working days; holidays; start/end trigger.	Written or portal evidence for the specific booking/container.	Wrong tariff or clock; free time expires unnoticed.
03	Equipment and cargo scope	20GP/40GP/40HC/Reefer/OOG, dry/DG/temperature-controlled, SOC/COC.	Correct tariff and conditions for equipment and commodity.	Dry-container terms are incorrectly applied to reefer or special equipment.
04	D/O/eDO release conditions	Original B/L or telex release, authorization, local charges, credit status, portal access.	D/O/eDO can be issued as soon as the cargo is releasable.	Customs-cleared cargo cannot gate out due to document or payment hold.
05	Customs-ready file	Invoice, Packing List, B/L, contract, HS, value, C/O, catalogue and declaration data.	Reviewed draft declaration with no open discrepancy or a documented treatment.	Late filing, document amendment, documentary inspection or physical examination.
06	Permits and specialized controls	Import permit, registration, quarantine, conformity, sampling location and authority.	Registration number, inspection slot and release/clearance condition.	Container waits for registration, sampling or the correct inspection location.
07	Taxes, C/O and funding	Estimated duties, C/O approach, bank limit, guarantee and approval.	Tax estimate, payer, deadline and fallback if C/O is not accepted.	Declaration is ready but tax obligations delay release.
08	Holds and terminal eligibility	Customs, carrier and terminal holds; manifest, seal, inspection and lifting status.	Container-level status table with hold owner and release evidence.	Truck arrives while terminal delivery remains blocked.
09	Trucking, warehouse and unloading	Terminal slot, truck/driver, route, warehouse slot, labor, forklift and unloading time.	Dispatch order, warehouse confirmation and fallback.	Container gates out but cannot unload, increasing DET.
10	Empty-return depot and DET closure	Designated depot, opening hours, equipment acceptance, condition check and EIR.	Primary/backup depot, internal cutoff and empty-return proof owner.	Wrong/full depot or rejected equipment causes late empty return.

FREE-TIME DECISION MATRIX

Question	Possible arrangements	Operational effect	How to verify
Separate or combined?	Separate DEM/DET or Combined D&D.	Separate clocks may allow different optimization; combined terms control total cycle time.	Booking, quotation, carrier portal and local tariff.
What days count?	Calendar days, working days or local holiday rules.	Weekends and holidays may still count.	Applicable POD tariff.
What starts the clock?	Discharge, availability, day after discharge or local event.	ETA cannot be the default start date.	Container events, terminal portal, carrier confirmation.
What stops DEM?	Full-container gate-out or another tariff event.	Customs release alone may not stop DEM.	Gate-out EIR and carrier terms.
What stops DET?	Valid empty acceptance at the depot.	Arrival at depot without acceptance may not close DET.	Empty-return EIR or portal event.
Is Storage separate?	Separate, collected on behalf of terminal or structurally combined.	Storage may expire on a different schedule.	Terminal and carrier tariffs.

DOCUMENTS AND DATA TO CHECK

Data group	Issuer/source	Owner	Fields that must align
Booking, B/L, Arrival Notice	Carrier/forwarder	Logistics coordinator	Vessel/voyage, POL/POD, terminal, container, consignee, ETA.
Free time and tariff	Carrier, quotation, portal	Procurement/logistics	D&D type, days, triggers, day type, equipment, effective date.
Commercial file	Seller/importer	Purchasing/trade team	Description, model, quantity, weight, value, Incoterms.
Customs file	Importer/broker	Customs compliance	HS, value, tax, C/O, regime, permits, transport data.
D/O/eDO and local charges	Carrier/agent	Documentation/accounting	Release status, B/L release, debt and authorized recipient.
Terminal/container status	Terminal/carrier portal	Operations	Discharged, available, hold, customs exam, gate-out eligibility.
Trucking/warehouse	Trucker/warehouse	Transport planner	Slot, driver, receiving time, unloading equipment.
Empty return	Carrier/depot	Transport planner	Depot, hours, equipment acceptance and EIR.

ETA-BASED CONTROL TIMELINE

Internal milestone	Action	Output	Escalation
D-10 to D-7	Confirm shipment, ETA, free time, permits, specialized controls, C/O and risk level.	Import-condition and free-time map.	Keep HOLD if policy or free time is unclear.
D-7 to D-5	Review commercial and transport documents, HS/value; open specialized-control files; estimate tax.	Version-controlled customs-ready file.	Escalate seller/forwarder discrepancies.
D-5 to D-3	Prepare draft entry; confirm B/L release, local charges, D/O/eDO and provisional warehouse slot.	Clearance and pickup plan with owners/deadlines.	Escalate funding or credit gaps.
D-3 to D-1	Update ETA/discharge; lock trucking, terminal slot, warehouse, unloading and return depot.	Dispatch plan and fallback.	Revise pickup if container is not available.
ETA to gate-out	Track discharge, D/O, declaration, taxes, inspections and terminal release.	Full-container gate-out EIR.	Trigger alert at internal free-time threshold.
Gate-out to empty return	Unload, inspect equipment, confirm depot, return empty and obtain EIR.	Empty-return confirmation; DET cycle closed.	Escalate depot changes, congestion or rejection.

RESPONSIBILITY MATRIX

Control	Primary owner	Support	Completion evidence
Free time/tariff	Logistics or procurement	Forwarder/carrier	Booking, email or portal record.
Customs-ready documents	Trade/customs compliance	Seller, broker	Controlled document set and draft declaration.
Permits/specialized controls	Compliance/trade	Authority/laboratory	Registration, permit and appointment.
D/O/eDO and debt	Documentation/accounting	Carrier/agent	Release status and settled debit note.
Trucking/warehouse	Transport planner	Terminal, trucker, warehouse	Slot, dispatch order and warehouse confirmation.
Empty return	Transport planner	Depot/carrier	Depot confirmation and return EIR.

COMMON RISKS AND ERRORS

Error	Cause	Impact	Control
Reusing prior free time	No shipment-specific confirmation.	Wrong days or trigger; unbudgeted charges.	Store free-time proof by shipment/container.
Tracking ETA only	No discharge/availability/hold monitoring.	Missed start of charge clock.	Track carrier and terminal events.
Customs cleared but no D/O	Customs and documentation teams work separately.	No gate-out despite clearance.	Run D/O/eDO and customs work in parallel.
Container pulled before warehouse readiness	No receiving slot or unloading capacity.	DET and truck waiting increase.	Confirm warehouse and unloading before gate-out.
Return depot not reconfirmed	Depot changes, congestion or equipment restriction.	Extra trucking and late return.	Reconfirm depot before truck leaves warehouse.
DEM confused with Storage	Only carrier tariff is checked.	Separate terminal charge is missed.	Review both terminal and carrier schedules.
No warning threshold	Action starts after invoice issue.	No time to request or purchase extra free time where offered, or to change the plan.	Alert by remaining free days and projected exposure.

OFFICIAL SOURCES AND APPLICATION

Official source	Role	Use
Maersk – Terms for Detention and Demurrage	Definitions of free time and DEM/DET/Combined/Storage.	Use for terminology; apply shipment tariff and booking.
Maersk – Demurrage & Detention explained	Explains container cycle inside and outside terminal.	Cross-check gate-out and empty return.
Hapag-Lloyd – D&D Tariffs Asia	Country tariff access.	Select correct country, direction and equipment.
Hapag-Lloyd – D&D Calculator	Shipment-level free-time/cost tool for supported countries.	As of 20 July 2026, Vietnam imports are not supported; use the tariff, local portal/office or written carrier confirmation.
CMA CGM – D&D General Terms	General import/export timing definitions.	Read with local tariff and booking.
MSC Vietnam – Local Information	Local eDO and release process.	Check portal, debit note, invoice and release.

PRIORITY RULE: The booking confirmation, B/L, quotation, local tariff and carrier’s shipment-specific confirmation prevail over a generic definition.

FAQ

1. Can ETA be used as the DEM start date?

Not by default. The trigger may be discharge, availability, the next day or another local tariff event.

2. Does customs clearance automatically stop DEM?

Not necessarily. DEM is usually linked to terminal/container status and gate-out, not only declaration status.

3. Is Combined D&D always better?

No. It offers flexibility across inside/outside time but the total pool remains limited.

4. Is Storage the same as DEM?

Not always. Storage may be a separate terminal charge or structured differently by location.

5. Should the container be pulled early to avoid DEM?

Only when the warehouse and empty-return plan are ready; otherwise DET may replace DEM.

6. When should extra free time be purchased?

Evaluate at booking and before ETA based on compliance, inspection, unloading and return risks. Purchase only where the carrier offers an eligible product or mechanism; do not assume every booking can be extended.

7. What proves empty return?

An empty-return EIR, depot acceptance or carrier portal event showing container number and timestamp.

APPLICATION NOTE: This is an operational control framework, not a substitute for the applicable tariff, transport contract or shipment-specific free-time confirmation. Days, triggers, holidays, rates and return depots may change.

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