Detention

Demurrage vs. Detention

Demurrage and detention are frequently confused, but they apply at different stages of the container's journey and are triggered by different events. Understanding the distinction is important because the charges are typically tracked and invoiced separately, and the strategies to avoid each are different.

• Demurrage charges accrue while a full import container sits at the port or marine terminal after the vessel has discharged it. The clock starts when the container is made available for pickup and stops when the container gates out of the terminal.
• Detention charges accrue after the container has left the terminal. The clock starts at gate-out (when the container is picked up by a truck) and stops when the empty container is returned to a designated depot or terminal.

In practice, an importer can incur both charges on the same container: demurrage if the container sits too long at the port before pickup, and detention if the container is held too long at the warehouse before the empty is returned.

How Detention Free Time Works

Similar to demurrage, carriers grant a set number of free days for the consignee to unload the container and return the empty equipment. Detention free time typically ranges from 4 to 7 days from the gate-out date, though this varies by carrier, port, and contractual terms.

The detention clock encompasses the entire round-trip cycle of the container outside the terminal: transit to the warehouse, unloading time, and transit of the empty container back to the carrier's designated return location. If any part of this cycle takes longer than expected -- slow unloading, trucker delays, or a return depot that is far from the warehouse -- detention charges accumulate.

Detention Rate Structures

Detention rates follow a similar tiered structure to demurrage, with daily charges that escalate over time.

• Standard Rates: Detention charges typically range from $75 to $150 per container per day during the first tier after free time expires.
• Escalating Tiers: After the initial period, rates may increase to $200 to $300 per day or more, depending on the carrier's tariff.
• Equipment Type: Rates may vary by container type. Standard dry containers typically have lower rates than refrigerated (reefer) containers, flat racks, or open-top containers due to the higher equipment cost.

Common Causes of Detention

• Slow Unloading: If the receiving warehouse is short-staffed, the container may sit on a chassis at the dock waiting to be unloaded for days. Floor-loaded containers (where cargo is loose, not palletized) take significantly longer to unload than palletized loads.
• Warehouse Appointment Delays: Warehouses that operate on appointment-only schedules may not have availability for several days, forcing the container to wait.
• Trucker Availability for Empty Return: Once the container is unloaded, a driver must pick up the empty and return it to the carrier's depot. If no driver is available, the empty sits at the warehouse.
• Return Depot Restrictions: Carriers sometimes restrict which depots accept empty returns, and those depots may have limited hours or capacity, creating additional delays.
• Chassis Shortages: In some markets, chassis availability is constrained. If an empty container cannot be moved because no chassis is available, detention continues to accrue.

Strategies to Minimize Detention

• Pre-schedule warehouse receiving appointments before the container arrives at the port to minimize dwell time.
• Prioritize floor-loaded containers for immediate unloading, as they take the longest and create the greatest detention risk.
• Establish relationships with multiple drayage providers to ensure empty return capacity is available when needed.
• Track the empty return deadline alongside the pickup deadline to manage the full container cycle, not just the inbound leg.
• Negotiate extended detention free time in carrier service contracts, particularly for high-volume lanes where warehouse scheduling is tight.

Tracking D&D with InboundShipments

InboundShipments tracks both demurrage and detention windows on every container, with support for 23 fee types on freight and customs invoices. By surfacing last free day and container gate-out dates, the platform helps teams manage the full D&D exposure across their inbound shipment portfolio and catch potential charges before they accrue.