Demurrage is a fee charged when your container sits inside the terminal past its free time; detention is charged when you keep the container outside the terminal too long; and per diem is the daily charge for using the ocean carrier’s container or chassis beyond the allowed period. All three are time-based penalties, but they apply at different stages of the container’s journey. Knowing the difference is the first step to avoiding them.
What is demurrage?
Demurrage applies while your container is still inside the marine terminal. After a vessel is discharged, the port grants a set number of “free days” to pick up the container. If the container is not removed before free time expires—because of customs holds, paperwork delays, or trucking shortages—the terminal charges demurrage for each additional day it occupies space.
What is detention?
Detention applies once the container has left the terminal. The ocean carrier allows a number of free days to unload (devan) the container and return the empty. If you hold the carrier’s container too long—because the warehouse is backed up or you cannot get a return appointment—the carrier charges detention for each extra day. In short: demurrage is “in the port,” detention is “outside the port.”
What is per diem?
Per diem is a daily charge for the use of the carrier’s equipment—most often the container itself, and sometimes the chassis—beyond the agreed free period. The terms detention and per diem are sometimes used interchangeably, but per diem specifically refers to the equipment rental clock. Chassis per diem is a frequent surprise charge for importers who do not control their own chassis.
How to avoid these charges
Pick up containers fast
The biggest driver of demurrage is slow pickup. Booking drayage early and predicting terminal gate times keeps containers moving before free time expires.
Control your chassis
Chassis shortages cause both delays and per-diem charges. A carrier with its own chassis pool can dispatch immediately instead of waiting on shared equipment.
Plan the unload and empty return
Schedule warehouse capacity and empty-return appointments in advance so the container does not sit and rack up detention.
Clear customs early
Customs holds are a leading cause of demurrage. Filing entries early and using bonded storage when needed prevents the container from being stuck at the terminal.
Avoiding container fees in Miami
Go Freight is an asset-based drayage carrier at PortMiami and Port Everglades with 100+ owned trucks and its own chassis pool, plus AI that predicts terminal gate times so drivers pull containers before storage fees hit. Freight can move straight into the company’s 104,000 sq ft bonded Miami warehouse, giving importers the speed and equipment control needed to keep demurrage, detention, and per diem to a minimum.
Frequently asked questions
What is the difference between demurrage and detention?
Demurrage is charged while the container is still inside the terminal past free time. Detention is charged after the container leaves the terminal and is held too long before the empty is returned.
Is per diem the same as detention?
They overlap. Detention generally refers to holding a container too long outside the terminal, while per diem specifically refers to the daily rental charge for the carrier’s container or chassis beyond free time.
How many free days do importers usually get?
Free time varies by port, carrier, and contract—often a handful of days for demurrage and a similar window for detention. Always confirm the exact free days on your specific booking.
Stop paying surprise container fees
Go Freight’s asset-based fleet and gate-time prediction keep your containers moving. Request a quote or call (786) 445-0150.