DEM/DET KNOWLEDGE HUB
Demurrage vs Detention: Understanding DEM/DET
Start a DEM/DET review by identifying which part of the container journey a charge covers. Inside versus outside the terminal is a useful starting point, but the applicable carrier tariff and shipment conditions determine the actual charging period.
What the two terms distinguish
Demurrage generally relates to a container remaining at a terminal or designated facility. Detention generally relates to using a container after taking it out and before returning it. Charges may arise when the Free Time allowed for the relevant period is exceeded.
Do not apply this distinction as a universal rule. Inland depots, transport arrangements, local terminology and Combined DEM/DET can change the boundaries. A charge name alone does not establish when its clock starts or stops. Identify the definition used for the shipment you are reviewing.
Events to check on imports and exports
For an import, relevant records may include discharge, availability for pickup, full-container gate-out and empty-container return. For an export, empty-container pickup, full-container gate-in and loading may matter. The tariff determines which events govern each charge. These are records to examine, not a universal list of charging triggers.
Vessel arrival, container discharge and availability for pickup describe different events. A vessel arrival record does not prove when a particular container was discharged or could be collected. Also distinguish actual timestamps from estimates when building your timeline.
Leaving a terminal does not necessarily end every charge. Gate-out may close one period while another continues. A Combined tariff may instead cover the periods before and after gate-out with one allowance. Confirm the charging structure before assigning an event to a charge.
Storage and other services
Terminal storage may be a separate charge for facility space. Do not assume it is included in demurrage or a Combined charge. Check the invoice item, charging party and stated coverage. Reefer power, monitoring and handling may also be separate services.
Several charges on one shipment do not by themselves establish duplicate billing. Review the service and period covered by each item. This guide explains how to organise that review; it does not determine invoice liability or the outcome of a dispute.
Fictional workflow: records before labels
Fictional example: an import container leaves a facility and is later returned empty. Knowing that transport, unloading and empty return occurred between those records is not enough to determine whether detention is due or how much it would be.
First check whether the shipment uses Separate or Combined terms. Then identify the specified start and end events, Free Time and counted dates. Movement records are inputs to that review, not substitutes for the tariff. No real carrier rule or rate is used in this example.
A short checklist before lookup
IndustryQuery provides automated results or official-source guidance according to the selected conditions, including for the same carrier. Set the conditions first, then use the official source to confirm applicability to your shipment. Avoid comparing numbers from different charging items as if they described the same cost.
Identify the carrier, country, port or region, and import or export direction.
Match DEM, DET or Combined to the item named in the official source.
Record the equipment and cargo type, and the relevant start and end events.
Check the day basis for Free Time and the charging period separately.
Confirm whether facility charges or additional services are included.