Demurrage and Detention Fees Explained: How to Avoid the Charges That Blow Up Your Landed Cost

Every landed cost formula has a line for "domestic transport and storage," and most importers budget it as a small, predictable fee. Then a container sits at the port two days longer than planned, and the bill arrives with a demurrage or detention charge that adds hundreds of dollars per container — sometimes more than the freight itself. Unlike duty or freight, this is one of the few landed cost components that's largely avoidable if you understand what triggers it.

In short: demurrage is a per-day fee the port or terminal charges for a container left in their yard past its free time; detention is the fee the carrier charges for their container/chassis equipment being held outside the terminal past free time. Both accrue daily, both are set by contract (not by law), and both are largely preventable with the steps below.

What Do Demurrage and Detention Charges Mean? They're Not the Same Fee

The two terms get used interchangeably, but they charge for different things:

Demurrage is charged by the terminal or port for a container sitting in the port/terminal yard past its free time, waiting to be picked up.
Detention is charged by the carrier (shipping line) for their equipment — the container itself — being held outside the port past its free time, usually while it's at your warehouse being unloaded or in transit to it.

In practice: demurrage covers the container sitting still, detention covers the container being "out" longer than allowed, whether that's during unloading or the return trip. Some carriers also charge a combined "per diem" that bundles both concepts under one rate.

What Triggers These Charges

Missed pickup window. Every shipment gets a set number of "free days" (commonly 3-5 for demurrage, similar for detention) before charges start accruing, usually per calendar day.
Customs holds. If your shipment is selected for exam or your paperwork isn't cleared, the free-time clock keeps running while the container can't move — this is the single most common cause of unplanned demurrage.
Trucking or chassis shortages. If you can't secure a trucker or chassis to move the container in time, you accrue charges even though the delay wasn't yours.
Slow unloading and return. For detention specifically, the container needs to be emptied and the equipment returned to a carrier-approved location within the free time — a warehouse backlog during peak season is a common cause.

How the Fees Are Calculated

Rates are almost always per container, per day, and they typically escalate the longer the container is held — day 1-3 overdue might be $75-150/day, then jump to$ 150-300+/day after that. Multiply by a chassis of containers on a single shipment and a few days of delay can turn into a four- or five-figure surprise on an order that looked profitable at the landed-cost estimate stage.

Because these fees compound daily and vary by port, carrier, and season, they're one of the hardest landed cost components to estimate in advance — which is exactly why they're worth actively managing rather than budgeting as a fixed percentage.

Typical Demurrage and Detention Rates by Range

Actual rates are set by individual carrier and terminal tariffs, but the ranges below are representative of what US and EU importers commonly see in 2026:

Days overdue	Typical demurrage (per container/day)	Typical detention (per container/day)
Days 1-3	$75 -$ 150	$100 -$ 150
Days 4-7	$150 -$ 225	$150 -$ 250
Day 8+	$225 -$ 350+	$250 -$ 400+

Rates step up in tiers rather than staying flat, which is why a delay that looks like "a few extra days" can double or triple in cost if it crosses into the next tier before you catch it.

How to Calculate Demurrage Charges: A Worked Example

The formula itself is simple — the hard part is knowing the exact free-time deadline. Here's how a calculation actually plays out:

Find your free time. Say your bill of lading grants 4 free days for demurrage, starting from vessel discharge on Monday. Your free-time deadline is Friday.
Track the actual pickup date. Customs holds your shipment for an extra exam, and the container isn't picked up from the terminal until the following Tuesday — 4 days late.
Apply the tiered per-day rate. At $125/day for days 1-3 and$ 200/day for day 4+: 3 days × $125 + 1 day ×$ 200 = $575 in demurrage on that single container.
Add detention if the equipment is also held late. If unloading and return of the container adds 2 more days beyond its detention free time at $150/day, that's another **$ 300**, for $875 total in demurrage and detention on one container — before duty, freight, or any other landed cost line.

Run the same math across a multi-container shipment or a customs hold that drags past a week, and it's easy to see how this single, avoidable line item can outweigh a duty-rate difference you spent hours modeling.

Chassis Demurrage and Chassis Detention

Some ports and rail ramps also charge separately for the chassis — the wheeled frame the container sits on for trucking — rather than bundling it into the container's demurrage/detention. Chassis detention works the same way as container detention: a daily fee for holding carrier- or chassis-pool-owned equipment past its free time. Chassis demurrage (less common terminology, sometimes called "chassis storage") applies when a chassis itself sits idle in a restricted yard. If your route uses a chassis pool (common at US rail ramps and some ports), confirm free-time terms for the chassis separately from the container — they don't always match.

A pre-pull charge isn't demurrage or detention — it's a drayage fee for pulling a container out of the terminal before you're ready to receive it, usually to avoid an approaching demurrage deadline, and storing it at the trucker's yard instead. It typically runs $75-$ 200 depending on the market. Pre-pulling can be a useful escape valve when a customs hold or warehouse backlog threatens to blow past free time — you trade a smaller, known pre-pull fee for a larger, uncertain demurrage bill — but it adds its own storage cost if the container then sits at the trucker's yard for several more days, so it only pays off when the wait is short.

How to Avoid or Minimize Them

File customs entry before the vessel arrives. Pre-clearance (or at least pre-filing) removes the single biggest cause of pickup delay — waiting on customs to release the shipment.
Book trucking and confirm chassis availability in advance, especially during peak shipping season when equipment shortages are common at major ports.
Negotiate free time upfront with your carrier or forwarder for recurring lanes — a few extra free days is a routine ask for regular volume and costs nothing if you don't need it.
Track free-time deadlines actively, not just container arrival dates — the clock often starts from discharge, not from when you're notified.
Have a fallback yard or overflow storage option for peak periods when your own warehouse receiving capacity is the bottleneck, not the port or carrier.

Building It Into Your Landed Cost Estimate

Most importers treat demurrage and detention as a rare exception rather than a real cost line — until it happens on a recurring lane and quietly erodes margin every cycle. If you ship regularly through a port or season with known congestion, it's worth adding a small buffer (even a conservative 1-2 days of expected overage) to your landed cost model rather than assuming zero, so a bad week at the port doesn't turn a profitable order into a break-even one.

Run Your Import Analysis →

For the full landed cost picture — including where demurrage and detention fit alongside duties, freight, and broker fees — see our step-by-step landed cost formula, and what to check before trusting a tariff calculator with the rest of the math. For exact per-day rate ranges and a worked cost example, see how much demurrage actually costs in 2026. Or run your own numbers with ImportCostPro's calculator for US imports (EU version for European importers).