Demurrage is charged while the container is still at the port. Detention is outside the port no matter full or empty.
To give you an example, imagine that a shipper or consignee has seven ‘free’ days once his or her container arrives at a port before they need to collect their cargo. If the cargo is not picked up by the consignee within the ‘free’ timeframe, then every day after, the shipper can be charged Demurrage by the day.
Once the shipper/consignee collects their cargo, there is a designated timeframe by which the container must be returned. If the consignee is not able to return the equipment within the allowed ‘free’ timeframe, every day after can be charged Detention by the day.
Each shipping line and port has specific definitions of these terms and may differ slightly, therefore, it is always a good idea to do further research.
