Detention & Demurrage: The Invoice You Can't See Coming

Two charges, two clocks

The industry uses "D&D" as shorthand for two distinct but related cost types that often appear on the same invoice, and are governed by different rules, different free-time periods, and different tariff schedules.

These charges can run concurrently when a container is slow to leave the terminal and then slow to be returned once it has been stripped. They can also be separate events: a container that moves smoothly through the terminal may still incur detention if the unloading and return cycle takes longer than the carrier allows.

Free-time terms are negotiated or published in the carrier's tariff. Standard free time varies by carrier, trade lane, and container type, typically 3-7 days for demurrage and 5-10 days for detention, though these vary widely and can be supplemented by negotiated additional free days. The terms that apply to a given shipment are those in the bill of lading, not the terms you remember negotiating with a sales representative.

Why the bills balloon

The D&D billing structure is asymmetric by design. Free time is generous at the start and becomes increasingly expensive as it runs. A typical escalation pattern looks like this:

This structure means that a container that sits for one extra week in the peak tier can generate more cost than the entire preceding 21-day period combined. By the time anyone notices, the bill is large enough to be a serious matter, but the window to intervene has long closed.

The documentation problem

D&D invoices arrive late. The carrier's billing system is triggered by the container's return to the depot, which may happen weeks after the container was picked up or stripped. The invoice then travels through the carrier's accounts-receivable system before reaching you. By the time it lands on a desk, the shipment record in your ERP is closed. The people who managed the shipment may not recall the specific timeline. The gate receipts and appointment confirmations that would allow you to verify the carrier's timestamps may not have been retained.

This timeline problem is why D&D is so resistant to dispute. The burden of proof sits with the party disputing the charge: you need to show that the container was available earlier than the carrier claims, or that the delay was caused by a terminal or carrier action, not by you. Without contemporaneous records, that case is hard to make.

Carrier clause asymmetry

Carrier tariffs are written by carriers. Free-time periods are measured against event timestamps recorded by the carrier's system: gate-in, gate-out, last free day, available-for-delivery notice. If there is a discrepancy between your records and the carrier's, the carrier's timestamps are typically treated as authoritative unless you can demonstrate an error. The practical implication is that any variation that is not tracked and documented in real time defaults to the carrier's version of events.

Port dwell and terminal congestion

Not all D&D is caused by importer delay. Terminal congestion, equipment shortages, vessel schedule changes, and customs holds can all extend the period before a container is available, or extend the period before a container can be returned. In some ports, chassis availability and appointment windows are constrained independently of what you do. When the clock is running and the delay is structural, the cost is real but the cause is not in your control. The distinction matters for both P&L attribution and for any recovery attempt.

Diagnosing where your D&D actually originates

Before escalating with a carrier or disputing a charge, the first step is understanding where the cost is actually coming from. This sounds obvious; most teams skip it and go straight to negotiation. The result is a dispute that lacks the specificity to succeed.

For each significant D&D charge, work through the following questions:

• When was the container available for collection? The availability notice date from the carrier should be cross-referenced against the actual free-time calculation in the invoice. If the carrier's system shows a date later than the actual availability, that is grounds for a timeline correction.
• When did the container leave the terminal? Gate-out timestamp from the terminal or the trucker's confirmation. If the container left on day 5 of an 8-day free-time period, demurrage should not apply. If it left on day 9, determine why: was the delay caused by a documentation hold, a customs examination, or simply a late pickup instruction?
• When was the container stripped and scheduled for return? The gap between gate-out and gate-in is the detention clock. If your warehouse turned the container in 3 days and the carrier is billing 8, there is a discrepancy worth investigating. If the turn took 8 days, understand why: was the container stuck waiting for a return appointment? Was there a port closure?
• Was there a customs examination or port authority hold? Customs examinations and ISPS inspections are typically excluded from free-time calculations under carrier tariffs, but only if they are documented and the exclusion is claimed. Failing to claim an exclusion you are entitled to is a common and avoidable cost.
• What does the free-time calculation actually say? Verify the carrier's stated last free day against the bill of lading terms. Errors in this calculation are not common but they occur, and a one-day error in last-free-day translates directly into a billing tier impact.

This forensic process requires data: carrier notifications with timestamps, trucker PODs with gate-out times, warehouse receiving logs, appointment confirmations, and customs release timestamps. Most of this data exists somewhere in the organisation. It is rarely assembled in one place in real time. That is the operational gap that D&D monitoring tools address.

What monitoring and recovery look like in practice

The first function of a D&D monitoring system is visibility: knowing which containers are actively running demurrage and detention clocks, in real time, rather than finding out when the invoice arrives. When you know a container entered day 8 yesterday, you can make an operational decision today (expedite the pickup, negotiate an extension, or arrange a container transfer) rather than absorbing the cost as a fait accompli.

The second function is dispute support. A system that logs event timestamps as they occur (available-for-delivery notice, gate-out, gate-in, vessel schedule changes, terminal closure days) builds the evidentiary record needed to dispute charges that should not have applied. Without this record, disputes rely on the importer's memory against the carrier's system.

The third function is trend analysis. Which carriers have the widest gap between promised and actual availability? Which lanes consistently run into the elevated charge tier? Which of your own facilities is slowest at returning equipment? This data changes how you negotiate free time in future contracts, how you route freight, and how you schedule warehouse resources.

Orca Flow, Orca Suite's transport management product, brings container tracking, carrier contract terms, and the demurrage clock into a single timeline. D&D monitoring and recovery is a built-in capability of Flow: free-time tracking across carriers, threshold alerts as containers approach the end of their free period, and dispute workflow with an audit trail. For teams that currently manage D&D via email threads and spreadsheets, this changes the operational baseline entirely. Learn more on the D&D capability page.

The commercial case for getting this right

D&D is often treated as an uncontrollable cost, one of those line items that varies, cannot be predicted, and is just absorbed into the margin. This is partly accurate and largely incorrect. The variable component is real. But a significant portion of D&D is predictable, trackable, and recoverable if you have the right infrastructure.

The commercial case is not just about recovering charges on disputed invoices. It is about including a realistic D&D expected value in landed cost models so that freight costs are not systematically understated. It is about choosing carriers and lanes where free-time terms, reliability, and equipment availability actually differ from the cheapest headline rate. And it is about having the documentation that makes a dispute viable rather than a futile exercise in retrospective frustration.

The invoice you cannot see coming only stays invisible for as long as you have no system watching the clocks. Once you do, it becomes a cost you manage rather than one that manages you.