Demurrage, detention and storage are three distinct charges that arise at different stages of container handling in maritime transport, yet they are routinely confused by importers, exporters and freight forwarders alike. Understanding the difference is not merely an operational matter – it carries significant legal and tax consequences.
Demurrage is charged by the shipping line for the time a container remains at the port terminal beyond the agreed free period, running from the moment the container is discharged from the vessel until it leaves the port gate. Detention, by contrast, begins once the container has left the port and continues until the empty box is returned to the carrier's designated depot. Storage is a separate charge levied by the terminal operator for the use of yard space, and it can run concurrently with demurrage – meaning the same container may generate two separate claims from two different creditors at the same time. Polish administrative courts, including the Regional Administrative Court in Gdańsk in a series of judgments issued in 2024 and 2025, have consistently applied these definitions in the context of VAT base calculations on imported goods.
Free time – the number of days during which no charges accrue – is the most frequent source of disputes. Its starting point is the container availability date, not the vessel arrival date or the date of customs clearance. The calculation rules differ between carriers and must be verified for each individual shipment. The freight forwarding associations have long advocated for automatic free time extensions in cases where the terminal itself is unable to release the container, for instance due to congestion or preferential treatment of carrier haulage over merchant haulage.
The most common causes of demurrage, detention and storage charges on the importer's side include delayed customs clearance, missing documentation, unavailability of inland transport and commercial decisions resulting in late pick-up. On the carrier and terminal side, port congestion, vessel rollings and unilaterally shortened free time periods are recurring issues. Importantly, when a container is seized by customs authorities, the carrier loses physical control over it and – as established by Belgian courts in 2019 – can no longer justifiably charge demurrage or storage from that point onwards.
Finally, a tax dimension that is often overlooked: demurrage, detention and storage costs constitute transport-related ancillary costs under Article 30b(4) of the Polish VAT Act and must be included in the taxable base for imported goods. Failure to declare them in the customs entry – even when invoices are issued after clearance – may result in additional VAT assessments by the fiscal authorities, with a five-year statute of limitations applying.