| What drayage covers | Short-distance container trucking from port or rail terminal to nearby facility |
| What triggers demurrage | Container remaining at terminal beyond the carrier's free-time window |
| What triggers detention | Container or chassis held outside the terminal past the allowed free-time period |
| Typical demurrage free time | 2–5 business days (varies by port and carrier contract) |
| Where detention accrues | After container leaves the terminal, while in shipper or consignee custody |
| Primary way to reduce exposure | Track free-time windows, coordinate warehouse capacity, submit customs docs early |
Three Charges, One Source of Confusion
For many US businesses shipping goods through ocean ports, three line items consistently appear on invoices without much explanation: drayage, demurrage, and detention. They sound similar, they often arrive together, and they can significantly inflate total shipping costs if left unmanaged. Yet each refers to a distinct service or penalty with its own trigger, clock, and responsible party.
Understanding these charges is not just an accounting exercise — it directly affects how you negotiate contracts, schedule pickups, and allocate warehouse resources. This reference breaks down each term clearly so logistics managers and business shippers can interpret their invoices and ask better questions of their carriers and terminal operators.
For broader context on freight terminology, see the Freight Terms Decoded reference guide, which covers foundational shipping vocabulary across modes.
| What drayage covers | Short-distance container trucking from port or rail terminal to nearby facility |
| What triggers demurrage | Container remaining at terminal beyond the carrier's free-time window |
| What triggers detention | Container or chassis held outside the terminal past the allowed free-time period |
| Typical demurrage free time | 2–5 business days (varies by port and carrier contract) |
| Where detention accrues | After container leaves the terminal, while in shipper or consignee custody |
| Primary way to reduce exposure | Track free-time windows, coordinate warehouse capacity, submit customs docs early |
Drayage: The Short-Haul Leg Nobody Thinks About
Drayage refers to the short-distance trucking move that carries a container from a port or rail terminal to a nearby warehouse, distribution center, or intermodal hub. Despite covering relatively few miles — often under 50 — drayage is a specialized service requiring chassis, port credentials, and scheduling coordination with terminal operators.
Drayage costs are typically quoted per container and vary based on distance, chassis availability, port congestion, and fuel surcharges. Because drayage sits at the critical handoff point between ocean or rail freight and over-the-road trucking, delays here ripple through the entire supply chain. Businesses using intermodal shipping should pay particular attention to drayage availability — as explored in how intermodal freight works.
A common misconception is that drayage is included in an ocean freight quote. It generally is not. Shippers should confirm whether drayage appears as a separate line item or is bundled into a door-to-door rate before finalizing any agreement.
Drayage
Short-haul trucking that moves a container from a port or intermodal rail terminal to a nearby warehouse or distribution point. It is a specialized service distinct from standard over-the-road trucking.
Demurrage
A fee charged by a port terminal or shipping line when a loaded container remains at the terminal beyond the allotted free-time period. It accrues daily and is designed to encourage prompt cargo pickup.
Detention (Per Diem)
A daily charge assessed when a container or chassis has been removed from the terminal but is not returned within the carrier or leasing company's free-time window. It applies while equipment is in the shipper's custody.
Free Time
The number of days a shipper is permitted to hold a container at a terminal or retain it after pickup without incurring demurrage or detention charges. Free-time windows are defined in carrier contracts or terminal tariffs.
Chassis
A wheeled trailer frame used to transport an intermodal container over the road. Chassis are often leased separately from containers and can generate their own per diem charges if not returned promptly.
Accessorial Charge
Any freight charge beyond the base transportation rate, including demurrage, detention, fuel surcharges, and liftgate fees. Accessorials are common sources of invoice surprises for shippers.
Demurrage: The Port's Clock Is Running
Demurrage is a fee charged by a port terminal or shipping line when a loaded container sits at the terminal beyond an allotted free time period — typically two to five business days depending on the port and carrier contract. It is designed to incentivize shippers to move cargo promptly so terminal space remains available.
Demurrage accrues daily, and rates escalate the longer the container remains. A container left at a major US port for a week past its free-time window can generate hundreds of dollars per day in charges. The fee is most often the shipper's responsibility, though the terms of your service contract will define exactly who is liable.
Customs Holds and Demurrage Liability
A US Customs and Border Protection (CBP) hold can prevent a shipper from picking up a container regardless of how well they've planned. However, most ocean carrier tariffs continue the demurrage clock even during a customs hold — meaning the shipper may still owe fees for delays outside their control. Some carriers offer exceptions or credits for government holds, but this is not universal. Always review your service contract's force majeure and hold provisions before cargo ships.
Common causes of demurrage include customs holds, delayed payment of freight charges, warehouse capacity issues, and inadequate trucking appointments. Shippers who consistently experience demurrage should audit their pickup scheduling process and ensure customs documentation is submitted well ahead of vessel arrival.
Detention: When the Container Leaves but Doesn't Return
Detention — sometimes called per diem — is the charge that kicks in when a container or chassis has been picked up from the terminal but is not returned within the carrier's or leasing company's free-time window. Unlike demurrage, which applies while the container is at the port, detention applies once the container is in the shipper's or consignee's custody.
If a warehouse is slow to unload, or if a chassis sits in a yard over a weekend, detention fees begin accumulating. Rates vary by carrier and equipment type but can range from $75 to $200 or more per day per unit. These costs are sometimes overlooked during freight budgeting because they occur away from the port and may not appear until weeks after the shipment.
Understanding how detention fits into your total freight cost picture is essential when reviewing quotes. The factors that drive freight quote variation often include accessorial charges like detention, which explains why two seemingly similar shipments can produce very different final invoices.
$75–$200+
Typical daily detention rate per container
Rates vary by carrier, equipment type, and contract terms; costs can compound quickly over multi-day holds.
2–5 days
Typical free-time window at US ports
Free time varies by port, terminal operator, and individual service contract; always verify the specific allowance before cargo arrives.
Managing These Costs Proactively
All three charges share a common characteristic: they are largely preventable with good planning and clear communication across the supply chain. Here are the core operational practices that reduce exposure:
- Track free-time windows precisely. Know the exact free-time allowance in your ocean carrier contract or terminal tariff before cargo arrives, not after.
- Coordinate warehouse receiving capacity with expected vessel arrival dates. Avoid scheduling conflicts that delay container pickup or unloading.
- Confirm chassis availability before booking drayage — chassis shortages at major ports are a persistent operational constraint.
- Submit customs documentation early. Customs holds are among the most common triggers for demurrage charges.
- Negotiate free time when possible. Larger shippers with volume may have leverage to extend free-time allowances in service contracts.
These charges are governed by tariff rules, carrier contracts, and terminal operating agreements — all of which vary. For decisions about your specific shipping arrangements, consult a licensed freight broker, customs broker, or logistics professional who can review actual contract terms on your behalf.
To understand how freight pricing structures work more broadly — including where these port charges fit — see our overview of freight shipping in the US.
This article provides general educational information about freight and logistics terminology. It is not legal, financial, or contractual advice. Specific charges, free-time periods, and liability terms vary by carrier, terminal, and contract. Consult a qualified logistics or legal professional regarding your specific shipping arrangements.