Spot the recoverable charge
Not all demurrage is recoverable, and trying to dispute every charge devalues the disputes that should succeed. Charges caused by port congestion, customs holds outside your control, equipment shortage at the carrier's facility, or terminal closure outside published hours typically are recoverable. Charges caused by your own delayed pickup, your own paperwork errors, or your own freight forwarder's missed deadlines typically are not. Build a screening rule into your finance workflow that flags only carrier-caused or terminal-caused events for dispute. The rule does not have to be perfect — it has to be consistent. A consistent screen produces a credible dispute pattern with the carrier's commercial team, which is what gets results.
Evidence in the carrier's format
Carriers reject claims with missing booking numbers, missing container numbers, missing free-time calculations or missing terminal proof. They have to: the carrier's revenue assurance team handles hundreds of disputes a week and needs a template. Build your claim pack with the carrier's exact field list: bill of lading number, container ID, free-time start, expected return, actual return, terminal acknowledgement and any government hold reference. Attach the carrier's own terminal report or the port community system record as your primary evidence — not your internal spreadsheet. The closer your claim pack looks to the carrier's internal format, the higher the first-pass approval rate.
Free-time calculations — the most common error
Free time is the period during which the carrier does not charge demurrage or detention. It varies by carrier, by trade lane, by container type and sometimes by contract. The most common dispute mistake is calculating free time from the wrong date — the bill of lading date, rather than the gate-out or last-free-day published in the carrier's tariff. Pull the tariff before you file, calculate the free-time window from the correct date, and show the calculation explicitly in the claim pack. Carriers cannot argue with their own published tariff.
Escalate, don't accept
First-line carrier responses are often 'denied — refer to tariff'. This is template language and does not mean the claim has been substantively reviewed. Escalation to the carrier's commercial team or your account manager, backed by your evidence pack and a tone of polite persistence, recovers 50–80% of legitimate disputes on the second pass. Track every claim by status — open, first-line denied, escalated, settled, written off — and never close one without a written outcome. The carrier's account team is graded on customer retention; a structured dispute pattern from a steady-volume importer is one of the few things that moves them.
Build the claim pack into the operation
The reason most importers do not recover demurrage is not that they cannot, but that the work to file a claim happens weeks after the event, when the evidence has scattered. Build the claim pack at the point of the event, not at the point of the invoice. The driver, terminal and forwarder all generate the evidence in real time; capture it in a single system at the moment of pickup or return, and the claim becomes a 10-minute filing rather than a 4-hour reconstruction.
Realistic recovery rates and timelines
On a structured programme, importers typically recover 30–50% of disputed demurrage value, with cycle times of 30–90 days from invoice to credit note. The biggest recoveries come from a small number of high-value events; the long tail of small charges is rarely worth the effort unless your claim process is automated. As a rule of thumb, every £1 invested in a structured claims process returns £4–£8 in recovered margin in the first year, and the multiple climbs as the carrier learns your pattern.
A consistent claim pack, a working escalation path, and the discipline to capture evidence at the point of the event turns demurrage from a write-off into recurring recovered revenue.