Demurrage
What is demurrage?
Demurrage is the daily charge for leaving a container inside a port, terminal or rail ramp beyond its free time. In US container shipping it is usually billed by the ocean carrier, sometimes by the terminal operator, under the tariff or contract that names who pays, and it grows by the day.
How it is measured
- Start: the event the terminal's tariff names (discharge, availability, or first gate-in).
- Free time: days added under that tariff, counted as business or calendar days exactly as it says.
- Last free day: the date the count lands on; from the next day, the daily rate begins.
- Release: demurrage stops when the container leaves the terminal; from then the per diem clock (often invoiced as detention by ocean carriers) runs until the empty is returned. Some carriers grant combined free time that covers both.
Winning a demurrage dispute
With the terminal's own rules and dates: the tariff page, the discharge event, every pickup attempt and refused appointment, and the free-time calculation. In the US, Federal Maritime Commission rules say these charges exist to get cargo moving, so days the container could not be collected can be disputed, and the invoice must carry the details the Commission's billing rule lists. Save the tariff page with the booking: a bill then takes minutes to reconstruct, and discovering the rule changed usually happens when the invoice arrives.