How to Audit a Drayage Invoice: Every Charge, Explained

Media

6 hours ago

Most shippers approve drayage invoices the way they approve utility bills: they glance at the total, decide it looks roughly right, and pay it. That habit is expensive. Drayage is the most accessorial-heavy leg in the entire supply chain, and the base rate is often less than half of the final invoice.

This is a line-by-line guide to reading a drayage invoice, knowing which charges are legitimate, which are negotiable, and which ones you should dispute every single time.

The anatomy of a drayage invoice

A drayage invoice usually has one linehaul charge and then anywhere from three to fifteen accessorials. The linehaul is the easy part — it is the negotiated rate for moving a container from the terminal to your door and back. Everything below it is where the money moves.

Charges that are almost always legitimate

Linehaul / base drayage rate. Should match your rate agreement exactly. If it does not, stop and reconcile before reading further.
Fuel surcharge. Legitimate, but it should be a defined formula tied to a published diesel index, not a flat percentage someone picked. Ask for the formula in writing.
Chassis usage. A real cost if the carrier is pulling from a pool. Should be a per-day rate with a stated daily amount and a clear start and stop date.
Terminal / port fees. Pass-through charges levied by the terminal. These should be passed through at cost with backup, not marked up.

Charges that are legitimate but frequently wrong

Detention. Charged when your facility holds the driver beyond free time. Legitimate in principle, constantly miscalculated in practice.
Per diem / container use. Charged by the ocean carrier for keeping the container past free days. Often billed for days when the terminal was closed or the container was not returnable.
Storage / demurrage. Charged when the container sits at the terminal past free time. Frequently billed even when the delay was caused by the terminal itself.
Pre-pull. Pulling the container before your delivery date to avoid demurrage, then storing it at the carrier’s yard. Legitimate strategy, but you should have authorized it.
Chassis split. Charged when the chassis and container are in different locations and the driver has to make an extra trip. Real cost, but it should be evidenced.

Charges to challenge by default

“Congestion” or “terminal delay” fees with no documentation. Ask for the in and out gate timestamps. If the carrier cannot produce them, the charge does not survive.
Dry run or TONU on a move that was cancelled with notice. Check your cancellation timestamp against the agreement.
Duplicate chassis days. Chassis billed for days the container was already returned.
Administrative or “documentation” fees that were never in the rate agreement.
Marked-up pass-throughs. If a terminal fee is $45 and you are billed $75, that is a margin line disguised as a cost line.

The audit process, step by step

Step 1: Reconcile the base rate first

Pull the rate agreement and confirm the linehaul matches. Roughly one invoice in ten has a base rate error, and finding it takes thirty seconds. Do this before you spend energy on accessorials.

Step 2: Build a timeline

Almost every disputable drayage charge is a time-based charge, which means almost every dispute is won or lost on timestamps. Assemble:

Vessel discharge date
Last free day for demurrage
Terminal out-gate timestamp
Arrival at your facility
Departure from your facility
Empty return in-gate timestamp

With that timeline in hand, every detention, per diem, and demurrage charge on the invoice becomes checkable arithmetic rather than a matter of opinion.

Step 3: Check free time against the timeline

Demurrage free time and per diem free time are different clocks with different start points, and they are the single most common source of overbilling. Confirm which days were actually chargeable — terminal closures, weekends where the terminal did not accept returns, and appointment unavailability all matter.

Step 4: Demand backup for anything time-based

A detention charge without gate timestamps is a claim, not a charge. Make “no documentation, no payment” a standing policy and communicate it to your carriers up front so it is not a surprise later.

Step 5: Track disputes to resolution

The reason overbilling persists is that most disputes are raised once and then dropped. Keep a simple log: invoice number, disputed line, amount, date raised, status. Carriers behave differently with customers who track.

The patterns worth watching over time

A single invoice audit recovers money. A pattern analysis changes your cost structure. After a quarter of auditing, look for:

Which lanes generate the most detention. Usually one or two receiving facilities are the problem, and the fix is operational, not commercial.
Whether per diem clusters around specific weeks. If so, you have a return-appointment problem, not a discipline problem.
Chassis days per move. A creeping average means containers are sitting somewhere they should not be.
Accessorials as a percentage of linehaul. Track this per carrier. A carrier with a low base rate and a 60% accessorial ratio is more expensive than one with a higher base rate and a 20% ratio.

That last metric is the one that matters most, and almost nobody tracks it. Carriers know that shippers shop on base rate, so the base rate is where they compete and the accessorials are where they earn. Comparing carriers on linehaul alone is comparing the wrong number.

Build the discipline into the contract

Auditing after the fact is defense. The offense is writing the agreement so there is less to audit:

Require that all accessorials be listed in the agreement, with the specific rule that any charge not listed is not payable.
Define the fuel surcharge formula and its index by name.
Require gate timestamps as standard backup on any time-based charge.
Set a documentation deadline — charges submitted more than a defined number of days after the move are not payable.
Require written authorization for pre-pulls and yard storage.

Five clauses. They take one conversation to negotiate and they eliminate most disputes before they exist.