Import fee benchmark
Per diem (detention): how often it hits and what it costs
The daily charge for keeping the carrier's container outside the terminal until the empty is returned.
The short answer. In our data, 3.7% of ocean container shipments into US ports were charged per diem (detention). When it was charged, the median bill was $370 per shipment. The middle half of bills ran from $185 to $870, and 1 in 10 was over $2,370.
Shipments from July 2024 to June 2026. Updated October 22, 2026.
What is per diem or detention?
Per diem, often called detention, is what the ocean carrier bills for each day its container stays out of the terminal beyond the free days allowed, counted until the empty box is returned. Demurrage covers time inside the terminal; per diem covers time outside it.
It usually builds up at the destination: a slow unload, a warehouse that is short of dock doors, no empty-return appointments, or a terminal that stops accepting empties for that carrier. Weekends and holidays often count.
Know the billing rules. Under the Federal Maritime Commission's demurrage and detention billing rule, in force since May 2024, ocean carriers and marine terminals must send these invoices within 30 days of the last day the charge accrued, include the details the rule lists, and give you at least 30 days to dispute. An invoice that misses those requirements does not have to be paid.
Per diem (detention) by port
How often shipments at each published port were charged per diem (detention). Ports with too few importers are left out, and a dash means too few bills to publish a cost.
| Port or rail hub | How often | Median bill | Shipments |
|---|---|---|---|
| Port Everglades | 8.5% | — | 94 |
| Minneapolis / St. Paul | 7.2% | — | 536 |
| Chicago | 5.5% | — | 712 |
| Omaha | 1.2% | — | 554 |
| Miami | 1.1% | — | 964 |
| Long Beach | under 0.7% | — | 736 |
| Los Angeles | under 0.9% | — | 578 |
| San Juan | under 1.1% | — | 460 |
| New York / New Jersey | under 1.5% | — | 343 |
| Houston | under 2.4% | — | 211 |
| Savannah | under 3.4% | — | 145 |
| Seattle | under 4.1% | — | 123 |
| Tampa | under 5.7% | — | 87 |
| All ports in the data | 3.7% | $370 | 8,298 |
How to avoid per diem (detention)
- Plan the unload before the box leaves the port, especially on drop deliveries.
- Ask whether free days are calendar or working days. The difference is large.
- Return empties promptly and keep the gate-in receipt as proof of the return date.
- If the terminal refused your empty, save the evidence. It is grounds to dispute the charge.
Questions
What is per diem or detention?
The daily charge for keeping the carrier's container outside the terminal until the empty is returned. Per diem, often called detention, is what the ocean carrier bills for each day its container stays out of the terminal beyond the free days allowed, counted until the empty box is returned. Demurrage covers time inside the terminal; per diem covers time outside it.
How often do importers pay per diem (detention)?
In our data, 3.7% of ocean container shipments into US ports were charged per diem (detention) at least once (95% range 3.4% to 4.2%).
How much does per diem (detention) cost?
When it was charged, the median per diem (detention) bill was $370 per shipment. Half of all bills fell between $185 and $870, and 1 in 10 was over $2,370.
Free quote
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