Shipping & Logistics
Demurrage & Detention
Also known as: Demurrage, Detention, Per Diem
Demurrage and detention are time-based penalty charges levied when containers or their contents overstay the free time allotted for loading, unloading, or return. Demurrage typically accrues when a full container sits inside the port or terminal beyond the allowed period awaiting pickup, while detention accrues when equipment is held outside the terminal — for example a container kept at a warehouse too long before being returned empty. These charges can escalate quickly during congestion and are a major, often avoidable, cost driver, so importers manage them through prompt clearance, efficient drayage, and close coordination with carriers and terminals.
These accrue daily, they accrue fast, and they are almost always caused by something that could have been prepared earlier — a missing agency data element, an unpaid invoice, a power of attorney nobody had signed. The cheapest demurrage is the kind avoided by having the entry ready before the vessel arrives.
Where it matters for compliance
- A customs hold or examination does not stop the clock — the charges accrue and you will be billed. Charges covering a period when the cargo could not have been retrieved may be unreasonable under the FMC's demurrage and detention rules, and there is a dispute process. You pay to get the box out first.
Related terms
Reviewed by a licensed customs broker. Definitions are general information, not legal or customs advice for a particular shipment. Duty rates, tariff programs and agency requirements change frequently.