Understanding the actual cost of delays at port
Detention and demurrage are two separate charges that shippers frequently confuse, and that confusion costs money every single day. Demurrage applies when your container sits inside the port terminal beyond the free time allowance. Detention applies once you pull the empty container out and it's still sitting somewhere outside the gate, whether that's your warehouse floor or a yard you're using for stuffing. MSC publishes tariff schedules that vary by port, trade lane, and container type. The base free time is typically three to five days at most US ports for domestic shipments, and slightly longer on certain trans-Pacific routes. But those numbers shift constantly. MSC adjusts free time quarterly based on terminal congestion data, and they have been tightening it across many European hubs since 2023. The per diem rates themselves are not uniform. A 40-foot high cube container at the Port of Long Beach might carry a demurrage rate of roughly $250 per day after free time, while the same container at the Port of Savannah could be closer to $175 per day. Detention rates follow a similar pattern but often start slightly lower in the first few days before ramping up. MSC also structures these rates ins, meaning the cost accelerates the longer the container is held. Days one through three past free time might cost one rate, days four through seven another, and beyond that it jumps significantly.
I dealt with a shipment last year where a carrier misclassified the equipment as a refrigerated unit rather than dry container, and the detention and demurrage schedule was completely different. The line had listed it as a reefer in their system even though the booking was for dry cargo. We caught it after three weeks because the daily charge on the invoice was far higher than the published tariff for dry boxes at that terminal. The fix required filing a formal tariff correction request with MSC's revenue team and providing the bill of lading along with the original booking confirmation showing the equipment type. It took about ten business days to get the adjustment, and in the meantime we were accruing the wrong rate on our books. The lesson here is that you should verify the equipment classification on your invoice against what you actually booked, not just assume the line has it right.
How the charges actually accumulate
Demurrage clocks start the day after the container is discharged from the vessel. If your vessel arrives on a Tuesday and the container is gated in by Wednesday afternoon, the free time begins Thursday morning. Detention clocks start from the moment the full container leaves the terminal gate. These are separate timers running on parallel tracks, and both can be active at the same time if your container is sitting inside the terminal and then gets pulled out later. MSC calculates free time based on the specific port terminal code, not just the city. Two terminals within the same port complex can have different free time allowances depending on which terminal operator runs them and what congestion levels the carrier has negotiated into their local tariff. Terminal A at a port might offer four days free while Terminal B, just two miles down the coast, offers only two. This distinction matters enormously when you are comparing quotes or reviewing invoices. One thing most shippers miss is that MSC offers conditional free time extensions in certain ports when congestion is severe. During the peak congestion period at Los Angeles and Long Beach in early 2022, MSC posted public notices granting extended free time at multiple terminals. These extensions were temporary and port-specific. They do not apply to every shipment arriving at that port. You have to check the current tariff notice for your specific terminal code to see whether an extension is active, because relying on general news articles about extended free time will lead to incorrect expectations.
Get the Full Details
Reading the MSC tariff schedule
The MSC tariff document you need is called the Detention and Demurrage Tariff for the specific trade lane. It is available on the MSC website under the service and products section, filtered by region. You want the document that covers your exact origin-destination pair, because rates differ between, say, Shanghai to Rotterdam and Ningbo to Hamburg even though both are Asian export lanes. The tariff will list free time by container type and port, followed by a per diem rate table. Some tariffs include a separate section for demurrage versus detention with different rate structures. Look for language around whether the rates are per container or per day, and whether there is a maximum cap on the total days of charges before the container must be returned or the shipment moved. MSC tariffs sometimes include a maximum charge period, which means after a certain number of days the daily rate either stops accumulating or switches to a storage rate, depending on the location. I routinely cross-reference the published tariff with the actual invoice using a simple spreadsheet. I pull the tariff rate for each port on my shipment list, enter the free time allowance, and then calculate the expected charge based on the number of days past free time shown on the invoice. If the variance exceeds a reasonable threshold, usually five percent, I flag it for review. This process catches errors like duplicated free time deductions, incorrect container size classifications, and days that were counted from the wrong reference date.
Where shippers get burned
The most common mistake is not knowing when free time actually starts. MSC counts free time in calendar days, not business days. Weekends and holidays count. If your container is discharged on a Friday and you have three days of free time, your deadline is Monday at the latest, assuming no holiday falls in that window. Many shippers budget for five working days and get surprised on Monday when the clock has already run out. Another frequent issue involves the handoff between demurrage and detention. When a container is picked up from the terminal, demurrage stops and detention begins. But if the trucking company gates the container back into the terminal for any reason, both clocks may restart independently. I had a case where a shipper's trucker had to return a container to the yard because the consignee was not ready to receive it, and the carrier charged demurrage again for the second gate-in period plus detention for the time the container sat at the yard waiting for pickup. The shipper argued that it was the same container and the charges were unfair, but MSC's position was that the equipment had left and re-entered the port environment, which triggered a new demurrage period. The contract language supports that interpretation, so the shipment ended up paying both. Free time can also be forfeited if the container is not picked up within a specified window after discharge. Some MSC tariffs include a no-free-time clause for containers that sit on the terminal apron beyond a certain point without being gated out. This is different from demurrage because it eliminates the free time entirely rather than charging a rate. It is rare but it does appear in certain congested ports during peak seasons, and it is not always prominently highlighted in the tariff summary that agents share with shippers.
Practical steps to control costs
Track your containers from discharge through delivery using a system that records the actual gate-in and gate-out times. Manual tracking via email threads and spreadsheets without timestamps will not give you reliable data. The difference between knowing and guessing how many free days you actually used can be the difference between a clean invoice and a dispute that drags on for months. Build a relationship with the local MSC office at your discharge port. The customer service team at the local station has more flexibility than the central billing department when it comes to contesting charges that seem unreasonable. I have had local MSC representatives waive a day or two of detention when the delay was caused by a documented terminal congestion event that the carrier was aware of but did not publicly announce. It is not guaranteed, and it does not work every time, but it is worth having a contact there rather than going straight to the revenue recovery department with a complaint. Negotiate free time as part of your rate contract. MSC will often grant additional free time if you commit to a minimum volume commitment on a lane. I have seen shippers secure an extra two to three days of combined demurrage and detention free time by negotiating it into their service contract, which effectively reduces the risk exposure on every shipment that hits a delay. Even a single extra day of free time at $200 per day saves you $200 per container that experiences a delay, and delays happen more often than most shippers expect.
Monitor the MSC tariff updates quarterly. The free time allowances and per diem rates change, and if you are operating on outdated assumptions you will be over or under budgeting for these charges. Set a reminder to pull the latest tariff for each of your active lanes at the start of each quarter. This takes about twenty minutes per lane if you know where to look, and it prevents surprises that show up on invoices three months into a new rate period. When you receive an invoice with detention or demurrage charges that you believe are incorrect, respond in writing within thirty days. MSC requires timely disputes, and charges that go unchallenged for extended periods can become harder to contest because the carrier will cite the passage of time as grounds for maintaining the billing. Your dispute should reference the specific invoice number, the container numbers involved, and the exact line item you are questioning, along with your calculation of what the correct charge should be. Attach supporting documents like gate receipts or proof of pickup and delivery times. Processing a dispute through the proper channel usually takes between two and four weeks, and most straightforward disputes are resolved without escalation.
