Demurrage is what you pay when a full container stays at the port terminal beyond its free time. Detention is what you pay when you keep the carrier’s container outside the terminal for too long before returning it empty. Both are charged per day, and both tend to climb in November and December, when Christmas stock is arriving and every link in the chain is busier. Getting your sea freight customs paperwork ready before the vessel arrives is the simplest way to stay inside free time, whether your boxes land at Felixstowe or elsewhere.
What is demurrage?
When a container is discharged from the ship, it sits in the terminal stack until it’s cleared and collected. Shipping lines allow a set number of free days for this. Once they run out, the line starts charging demurrage for every extra day the box stays put.
The terminal may also charge its own storage fees on top. The names vary between carriers and ports, and some lines combine the two into one charge, so it’s worth reading the terms on your booking rather than assuming.
What is detention?
Detention starts once the container has left the terminal. You have a set period to unload it at your warehouse or your customer’s site and return the empty box to wherever the line tells you. Keep it longer and detention charges start.
A container that waits a week for a forklift, or sits on a trailer because the warehouse is full, can quietly build up a bill that nobody budgeted for.
Why the charges climb before Christmas
Peak season puts pressure on every part of the process at once:
- More boxes arriving together. Retailers and wholesalers bring stock in ahead of Christmas, so terminals and hauliers are stretched.
- Haulage is harder to book. If you can’t get a slot for collection, the container waits in the stack while the free days tick by.
- Warehouses fill up. Delayed unloading means delayed returns, which leads to detention.
- The holiday period itself. Fewer working days over Christmas and New Year can mean slower collection and returns.
None of this is unusual, but it does mean small delays cost more than they would in a quiet month.
Customs holds and free time
One of the most avoidable causes of demurrage is a container that can’t be released because the customs declaration isn’t ready or has been queried. Missing commercial invoices, unclear goods descriptions and the wrong commodity code are common culprits, and we’ve covered several of them in our guide to the reasons shipments get delayed at customs.
If customs selects a container for a physical examination, it may need to be moved to an inspection area, and that can take time. You can’t always prevent an exam, but you can make sure the paperwork is complete so that once the goods are released, nothing else holds them up.
Practical ways to reduce the risk
- Know your free time before the box ships. Ask your forwarder or the line how many free days apply at the port of discharge and for return.
- Send documents early. Commercial invoice, packing list and any licences or certificates should reach your customs broker before arrival, not after.
- Book haulage in good time. In peak season, waiting until the container is released can be too late.
- Plan the unload. Make sure there’s space, labour and equipment at the delivery address.
- Watch the return location. Empty containers sometimes have to go back to a depot, not the port, so check the instructions.
Container ports on the East and South coasts
Most deep sea containers for UK importers come in through the big East and South coast ports. Felixstowe, Southampton and London Gateway all handle large volumes of Christmas stock, and each has its own terminal rules and charges. Whichever port your goods use, the same principle applies: clear customs quickly, collect promptly and return the empty box on time.
Frequently asked questions
Who pays demurrage and detention charges?
It depends on the contract and the Incoterm agreed between buyer and seller. In many import shipments the consignee ends up paying because the delay happens on the UK side. Check your sales terms and your carrier’s tariff, and agree who is responsible for any delays at destination before the goods are shipped.
Can I ask for more free time?
Some shipping lines and forwarders will agree extra free days, particularly for regular customers or when the request is made at the booking stage. It’s much harder to negotiate once the charges have started. If you know a shipment will be slow to unload, raise it early and get any agreement confirmed in writing.
Does a customs examination stop the demurrage clock?
Not usually. Free time and charges are set by the shipping line and terminal, not by HMRC, so a box waiting for an examination can still build up demurrage and storage. Complete, accurate paperwork reduces the chance of queries and helps the container move as soon as it’s released.
Talk to us before your next container lands
Give us a call on 01304 759200 or drop us a message and we’ll look at your upcoming shipments, get the customs side ready before arrival and help you keep inside your free time.