The Clock Nobody Watches: What a Container Really Costs When It Sits at Mombasa

Storage fees and demurrage can outrun the freight bill. The charges are predictable, and the warning arrives before the ship does.

Ask an importer what a container costs to bring into Kenya and the answer usually begins with the freight rate and ends with the customs duty. Few mention the clock. Yet at the Port of Mombasa the clock is running from the moment a box touches the quay, and for those who lose track of it, the bill can arrive long after the goods have cleared and the sense of relief has set in.

The charges are not mysterious. They are published, they are predictable and, for the most part, they can be planned around. The difficulty is that they come from three different sources, run on different rules and rarely appear on the same statement.

Three clocks, three bills

The first clock belongs to the Kenya Ports Authority. Its published storage terms give domestic import containers five free days, and transit containers 15. Once that window closes, storage is billed per day. For domestic imports the reported rate is USD 30 a day for a 20 foot container and USD 60 a day for a 40 foot box between days 6 and 21. After day 21 the rates rise to USD 50 and USD 100 respectively. Transit cargo pays the same daily rates once its 15 day allowance is spent.

The second clock belongs to the shipping line, and it is the one that catches most importers out. Each carrier sets its own free time and its own demurrage tariff, which varies by line, container size and destination, so there is no single figure that applies to every consignment. Press reports earlier this year put shipping line demurrage at Mombasa at roughly KSh 1,677 to KSh 12,900 per container per day, or about US$13 to more than US$100. The number on the booking confirmation is the one that matters, and it is worth reading before the vessel sails.

The third clock starts once the container has left the terminal. Detention is charged if the empty unit is not returned within the carrier's permitted time. A box can clear the port storage window and still generate detention, because nobody booked the truck to the empty depot or the empty return appointment. Ask the line to confirm your last free day and the correct return location in writing.

Why the clocks are running faster this year

Congestion has made all three harder to manage. Reports earlier this year described empty container depots around Mombasa full for weeks, transporters queuing for up to five days to return empties and turning away when the yards were full, and importers disputing demurrage levied during a backlog they had no part in creating. The port's own managing director has acknowledged a serious shortage of storage space.

Congestion is beyond the reach of any single importer. Much of the delay that does cost money is within reach, though, and it tends to come from five familiar sources: documents that are late or inconsistent; duty that is assessed but not yet funded; a container nominated to a freight station with no confirmed slot; a bill of lading that does not match the manifest; and no truck, delivery slot or empty return plan waiting when the box is released.

The new paperwork that cannot be skipped

Since 3 August 2026, containerised cargo bound for Kenyan ports has needed an Advance Cargo Declaration reference code before it is loaded. The exporter obtains the code on the Kenya Revenue Authority's platform by uploading a draft bill of lading, the commercial invoice, the freight invoice and the export declaration. The code must then be endorsed on the bill of lading. Carrier notices warn that a shipment arriving without it can expose the importer to customs fines.

This is the most consequential change for dwell time this year, and it is the easiest to miss. A missing code does not stop a ship; it stops a container at the moment it is most expensive to wait. Ask the supplier to confirm the code is being generated, and ask the clearing agent to check that it appears on the bill of lading before the ship sails.

Book the space, then the truck

Container freight stations and warehouses fill quickly when several vessels arrive together, and a container cannot be devanned or released without a confirmed slot. Once the entry is in progress, the sensible sequence is to book the freight station or warehouse space and, for inland cargo, the truck or rail movement at the same time.

Rail has become a serious option. The Mombasa to Nairobi standard gauge railway has now carried more than 50 million tonnes of freight since operations began, and importers increasingly choose it for predictable transit. Ask your forwarder whether a rail slot is available before defaulting to road. Transit cargo needs a further check: the bond, the route and the handover at the border should all be agreed before the container leaves the port.

Money in place before the box lands

Duties and taxes are settled against the customs entry, and release follows assessment and payment. The most avoidable delay in the sequence is the gap between an assessment being issued and the payment being made. Estimate duties and statutory charges before arrival, secure internal approval in advance, and agree who will send the payment confirmation to the agent. A payment instruction is not a receipt, and a receipt is not a release.

The discipline that pays

The importers who avoid these charges tend to share one habit: they track time as carefully as they track cost. A simple milestone record, covering vessel arrival, discharge, customs entry, payment, release, gate out and empty return, with the KPA and carrier deadlines beside each step, will show quickly whether a delay came from documents, funding, customs, the terminal or the carrier. That record is the best argument for changing the next shipment's plan.

A low freight rate can be undone in a week of idle time. The protection is a pre arrival routine that the importer, shipper, agent, shipping line and transporter all understand, with one named person responsible for each deadline.

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Sources

1. DHL Kenya, "How to avoid demurrage charges when importing goods into Kenya" (KPA storage free days and rates): dhl.com
2. Kenya Revenue Authority, public notice on the Advance Cargo Declaration platform (14 July 2026): kra.go.ke
3. Kenyans.co.ke, "KRA introduces new digital cargo declaration system for goods shipped to Kenya" (July 2026): kenyans.co.ke
4. Maersk, "Kenya ACD mandatory imports update" (July 2026): maersk.com
5. Business Today, "Port users protest demurrage fees as Mombasa congestion drives up trade costs": businesstoday.co.ke
6. Capital FM, "SGR freight volume surpasses 50mn tonnes" (July 2026): capitalfm.africa

General information, not legal advice.

Sidoman Logistics, Mombasa