A container can arrive on time, clear customs without issue and still become expensive while it sits at the port. Demurrage charges explained simply: they are fees charged when a loaded container remains within a port, terminal or carrier-controlled area beyond the agreed free time. For UK importers, these costs can escalate quickly, particularly where documentation, customs clearance, collection arrangements or delivery slots are not ready.
Demurrage is not merely a shipping-line issue. It is usually the result of a handover problem between several moving parts: the vessel arrival, release of shipping documents, customs status, haulier availability, warehouse capacity and the consignee’s ability to receive goods. Managing those stages early is the most reliable way to protect both delivery schedules and landed cost.
What are demurrage charges?
Demurrage is a daily charge for keeping a full import or export container at the port or terminal after free time has expired. The precise charge, free-time allowance and calculation method depend on the carrier, port, service, trade lane and contract. Charges may increase in bands, so the daily rate after several days can be materially higher than the rate at the start.
For an import shipment, free time typically begins from vessel discharge, container availability or a defined terminal event. It ends when the laden container is collected from the port. If the collection happens after the permitted period, demurrage applies.
For an export shipment, the principle can differ. A packed container delivered to the port too early may incur storage-related costs or export demurrage, depending on the booking terms and terminal procedures. This is why the shipping instruction, carrier booking confirmation and port guidance should be checked before cargo is moved.
Demurrage, detention and storage are different costs
These terms are often used interchangeably, but they relate to different stages of the container journey. Understanding the distinction helps identify where a delay occurred and who can take action.
Demurrage applies while the loaded container remains at the port or terminal. Detention normally applies once the container has left the terminal but has not been returned empty to the nominated depot within the carrier’s permitted time. Storage is charged by the terminal or port operator for occupying space in its facility, and it may be payable alongside demurrage.
A container delayed at Felixstowe because customs has not cleared could therefore generate terminal storage and carrier demurrage. Once it is collected, the risk shifts: a delayed devanning appointment or difficulty returning the empty box may create detention instead. The invoices may come from different parties, with different payment deadlines.
Why demurrage charges arise
The most common cause is that the container is not ready for collection before free time expires. That can happen for straightforward reasons, such as a late arrival notice, but more often it is a combination of operational delays.
Customs holds are a frequent trigger. An incorrect commodity code, incomplete commercial invoice, missing licence, unclear goods description or a requirement for documentary or physical examination can all prevent release. Duty and VAT arrangements must also be in place. A customs entry filed late, or filed with incomplete information, leaves little time to resolve queries before charges begin.
Document release is another pressure point. Depending on the shipment terms, the consignee may need an original bill of lading, express release, sea waybill confirmation or carrier release before the container can leave. Where freight, destination charges or security deposits are outstanding, the release may also be delayed.
Collection then depends on practical capacity. The haulier needs a port slot, a vehicle, the correct reference numbers and confidence that the container is available for collection. The delivery point must have a booking slot, equipment to unload where needed, suitable access and space for the goods. If a warehouse cannot accept the container until the following week, free time may already have been consumed.
Port congestion, vessel schedule changes, blank sailings and late discharge can make planning harder. However, these risks do not automatically remove demurrage liability. It depends on the carrier’s published terms, the nature of the disruption and any agreed contractual arrangements.
How free time works in practice
Free time is not a standard entitlement across all shipments. Some carrier tariffs allow only a few calendar days, while others offer a longer allowance. Weekends and bank holidays may count, and the clock may run even when collection slots are limited. Never assume that five free days means five working days.
The key details to establish before arrival are the number of free days, the start event, the final free day, applicable daily rates, whether port storage is separate and the empty-return deadline. These should be reviewed against the actual expected vessel arrival rather than the original sailing schedule.
It is also worth checking whether free time is calculated by calendar day, working day or a specific cut-off time. A container discharged late on a Friday can become urgent sooner than expected if Saturday and Sunday count. The position can be different for each carrier and terminal, so a general rule of thumb is not enough for cost control.
How to reduce demurrage risk
The strongest approach is to prepare the clearance and collection plan before the vessel arrives. Once a container is available, each day matters. Importers should provide commercial invoices, packing lists, commodity details, Incoterms, origin information and any product-specific certificates well in advance. Where a shipment is high value, controlled, dangerous or subject to food, plant or product regulations, allow additional time for checks.
A clear delivery plan should be agreed at the same stage. Confirm the delivery postcode, site restrictions, unloading equipment, receiving hours, booking requirements and whether the container will be live-unloaded or grounded. Live unloading can reduce equipment and handling requirements, but it relies on the site being ready when the vehicle arrives. Grounding a container offers more flexibility for unloading, yet it can increase detention exposure if the empty unit is not returned promptly.
For regular volumes, it may be commercially sensible to negotiate additional free time as part of the ocean freight arrangement. This is not always available and may affect the freight rate, but it can be worthwhile for cargo moving to congested destinations, warehouses with limited appointment capacity or sites far from the port. The decision should be based on the likely total cost, not the headline sea freight price alone.
When a delay becomes unavoidable, act before free time ends. Ask the carrier or its agent whether an extension can be purchased or approved, and obtain the terms in writing. An extension is not guaranteed, especially during periods of high equipment demand or terminal congestion, but early communication gives more options than waiting for an invoice.
Who is responsible for paying demurrage?
Responsibility depends on the contract of carriage, Incoterms, booking arrangements and the reason for delay. In practice, the party named as consignee or contracting customer may receive the invoice first, even where another party contributed to the delay. Recovering costs from a supplier, buyer or third party can then become a separate commercial matter.
Incoterms help define obligations between buyer and seller, but they do not override a carrier’s terms. Under FOB, for example, the buyer may control the main carriage and destination arrangements, so it will usually need a clear import plan. Under DDP, the seller may take greater responsibility for delivery and import formalities, but the exact contract and customs representation arrangements still matter.
If demurrage appears to have resulted from a carrier, terminal or customs-related issue outside the consignee’s control, retain evidence. Arrival notices, release messages, customs communications, port screenshots, collection booking records and emails can support a dispute or waiver request. A successful challenge is never certain, but a well-documented timeline is far more persuasive than a general complaint after charges have accumulated.
A practical arrival checklist
In the week before vessel arrival, confirm the estimated arrival date and free-time terms, finalise customs data, check that all shipping documents can be released and ensure funds or deferment arrangements are ready for duty and VAT. At the same time, secure a delivery plan with the receiving site and make sure the haulier has the references needed for collection.
After discharge, monitor container availability and customs status daily. If an examination, document query or delivery problem arises, assess the impact immediately rather than assuming it will be resolved before the deadline. A prompt change of delivery date, use of temporary storage or request for extra free time can be less costly than allowing demurrage and storage to run unchecked.
Milky Way Logistics coordinates sea freight, customs clearance, port collection, temporary storage and onward delivery as one operational process, helping importers identify pressure points before they become avoidable charges. For a shipment with tight free time or complex customs requirements, request a tailored, no-obligation freight quotation early enough to build a workable arrival and delivery plan.
