Demurrage and Detention: When a Container Becomes Expensive Standing Still

Treat the sections below as a sequence. With charges for holding shipping equipment, getting the early decisions right makes the later ones much easier.

Two clocks, two places

Demurrage in container shipping usually refers to charges for cargo remaining in the terminal beyond the free time allowed. Detention usually refers to charges for keeping the container itself outside the terminal beyond its allowance after collection. The terms are used inconsistently across regions and carriers, so the tariff wording matters more than the label.

Both exist because the equipment and the yard slot are scarce and the carrier wants them back in circulation. Understanding which clock is running determines whether the fix is faster clearance or faster unloading and return.

Why the charges escalate

Free time is typically a few days, after which charges apply per container per day and often increase in tiers. The escalation is deliberate, since a flat daily rate would allow shippers to treat containers as cheap storage. Because the rates compound across many containers, a delayed shipment can generate charges comparable to the freight itself.

The charges accrue whether or not the delay was within the importer's control, subject to specific relief provisions. That allocation of risk is set by the contract of carriage rather than by any general principle of fairness.

Common causes of accrual

Customs holds, incomplete documentation and inspection selection are frequent causes on the terminal side. Missing or late payment of charges, incorrect consignee details and unregistered parties add avoidable delay.

On the detention side, warehouse capacity, unloading labour and transport availability determine how quickly boxes are returned. Congestion at the return depot can prevent return entirely, and whether relief applies then depends on the tariff and local rules. Most accrued charges trace to a small number of repeated causes rather than to unpredictable events.

Negotiating the allowance

Free time is a commercial term and is regularly extended for shippers with volume or as part of a rate negotiation. Extended free time can be worth more than a small reduction in the base rate for importers with slow inland processes. Terms can also be negotiated per lane, since congestion and clearance times differ substantially between ports.

Firms that never raise this typically operate on the carrier's standard allowance without knowing an alternative exists.

Reviewing accrued charges by lane over a year usually shows where an extended allowance would pay for itself.

Disputes and relief

Some jurisdictions have introduced rules requiring charges to be reasonable and to serve their stated purpose of freeing equipment. Where a container could not physically be returned, arguments about whether charges should apply have been raised in several places.

The legal position varies and continues to develop, so relying on it is less reliable than preventing accrual. Documenting the cause of each delay contemporaneously is what makes a later challenge possible at all. Without that record, a dispute becomes an assertion against a carrier's system-generated invoice.

Designing the process to avoid it

Filing customs entries before arrival, where permitted, removes the most common source of terminal delay. Pre-booking transport against the vessel schedule rather than against arrival notices shortens collection time.

Upstream of that, holding some warehouse slack during peak season prevents the situation where containers cannot be unloaded on arrival. Monitoring free time expiry by container, with alerts, converts a monthly surprise into a daily operational task. These measures are ordinary process discipline, and they address the majority of charges most importers incur.

The takeaway

Know which clock is running and when it started. This is general information about shipping practice, not legal advice.

Somebody pays the tariff. The argument is only ever about who.