Freight audit · Errors and disputes

Freight Billing Errors: 9 Overcharges and the 180-Day Clock

Published September 13, 2026 · Rob Eller

Across the programs we audit, disputable errors typically touch two to five percent of invoice dollars. They are not random. The same nine freight billing errors recur on less-than-truckload (LTL), truckload, and parcel bills, each with a known cause, a known place on the invoice, and a known piece of evidence that settles it. And every one of them sits on a clock: for interstate motor carriers, 49 USC 13710 gives you 180 days from receipt of the bill to contest it, and gives the carrier 180 days to bill you anything more.

Freight billing error · Any charge on a carrier invoice that differs from what the controlling contract, tariff, and shipment documents say it should be. An overcharge if it favors the carrier; an undercharge if it favors you.

Duplicate freight bill · A second invoice for a shipment already billed, under the same PRO number (the carrier's shipment number) or a new one, including balance-due bills issued while the original remains open.

Balance-due bill · A supplemental invoice for additional charges on a shipment already billed, usually after a reweigh, reclass, or late-added accessorial. Collectible only if issued within 180 days of the original bill.

Overcharge claim · A written demand to the carrier for refund of an amount billed above the lawful or contracted rate, with the invoice, the controlling document, and the math attached.

Industry context

Across the freight audit industry, Trax Technologies cites 5–7% average annual savings on enterprise transportation spend, AFS Logistics claims up to 8% recovery on freight audit programs, and ConData reports identifying $645M in carrier overcharges across its enterprise client base. Programs without an active audit routinely run 4 to 7 percent leakage. The errors below are what that leakage is made of.

The nine freight billing errors

Listed roughly by dollars at stake on a mixed LTL, truckload, and parcel program. The evidence column is what wins the dispute; without it, you have an opinion.

#	Error	Mode	How it shows on the bill	Evidence that settles it	Typical size
1	Reclassification	LTL	Billed class higher than the bill of lading (BOL) class	Inspection certificate with measured dimensions; density math	5 to 25% of linehaul
2	Unauthorized or undocumented accessorials	LTL, parcel	Liftgate, residential, limited access, inside delivery not on the BOL	BOL, delivery receipt, proof of delivery; contract accessorial exhibit	$50 to $150 per line
3	Duplicate billing	All	Same shipment invoiced twice; balance-due plus original both open	PRO, ship date, origin, destination, weight match; payment record	Full invoice amount
4	Fuel surcharge	All	Wrong index week; applied to gross or to accessorials	Energy Information Administration (EIA) reading for the pickup week; carrier table; contract fuel clause	0.5 to 3% of linehaul, every shipment
5	Wrong rate, discount, or tariff base	LTL, truckload	Net linehaul does not match the contract; drifts after a rate increase	Contract rate exhibit with tariff base name and effective date	3 to 40% of linehaul
6	Reweigh	LTL	Billed weight above BOL weight; often crosses a weight break	Certified scale ticket; product and pallet weights; deficit weight check	$20 to $200
7	Dimensional weight adjustment	Parcel	Billed weight above declared; adjustment fee added	Carton specification; dimensioner record; contract divisor	$2 to $10 per package plus fee
8	Minimum charge misapplied	LTL	Absolute minimum charge (AMC) billed above the discounted rate, or tariff AMC billed over the contract AMC	Contract minimum charge schedule by lane	$20 to $90
9	Wrong party or wrong terms	All	Prepaid shipment billed collect; third-party shipment billed to shipper; both billed	BOL terms box; routing instructions	Full invoice amount

Errors 1, 2, and 6 are frequently legitimate charges caused by the shipper's own inputs, and the evidence decides which. Errors 3, 4, 5, 8, and 9 are almost always the carrier's. Error 7 is a mix. The LTL mechanics are worked on the LTL shipping page; the parcel-specific errors on the parcel audit and dimensional weight pages.

How duplicate freight bills actually happen

Nobody at a carrier sets out to bill a shipment twice. It happens through five ordinary mechanisms, and an accounts payable (AP) match on PRO number catches only the first.

Same PRO, transmitted twice. An electronic data interchange (EDI) 210 invoice is sent, fails an acknowledgment, and is re-sent. Or the EDI file and a paper copy both arrive and both get keyed. The simplest form and the only one a PRO match catches.
Balance-due bill with the original still open. The carrier reweighs or reclasses and issues a supplemental bill for the difference. Correct practice is a bill for the delta. Common practice is a new bill for the full re-rated amount, while the original is still in your AP queue. Both get paid.
Rebill under a new PRO. A correction to the bill-to party, the terms, or the address generates a new PRO. The old one is supposed to be cancelled. It is not always. Two PROs, one shipment, no match on number.
Shipper and third party both billed. The BOL says third-party billing to your logistics provider; the carrier's system defaults to the shipper on the BOL. Your provider pays it, and so do you. The reverse happens on prepaid shipments billed collect to the consignee, who pays and then deducts it from your next remittance.
Master and child PROs. Multi-piece or split shipments get a master PRO and one per piece. The master is billed for the whole, and one or more children are billed again.

The match that catches all five is not on PRO number. It is on ship date, origin zip, destination zip, and weight, with a tolerance, across every invoice from every carrier in the window, and then a human look at the pairs. Duplicate rates on the programs we see run 0.2 to 0.5 percent of invoices. On 60,000 invoices a year at an average $612, 0.3 percent is 180 duplicates and $110,160 paid twice.

The 180-day clock, and the 18-month one behind it

Two federal deadlines govern overcharge disputes with interstate motor carriers, and they run in opposite directions.

Your 180 days. Under 49 USC 13710(a)(3)(B), a shipper must contest an original or subsequent bill within 180 days of receiving it in order to preserve the right to contest the charges. The clock starts on receipt of the bill, not on the ship date and not on the payment date. A carrier can give you longer by contract, and some do; the statute is a floor, and a contract that tries to shorten it below 180 days is on weak ground.

The carrier's 180 days. Under 49 USC 13710(a)(3)(A), a motor carrier must issue any bill for charges in addition to those originally billed within 180 days of your receipt of the original bill in order to have the right to collect them. A balance-due bill for a reweigh that arrives on day 200 is not collectible. Most AP teams pay it anyway because it looks like a bill. On one program we reviewed, 41 late balance-due bills averaging $340 had been paid in a year: $13,940 the carrier had no right to.

The 18 months. If a dispute is not resolved, 49 USC 14705 requires a civil action to recover an overcharge to be filed within 18 months of when the claim accrues, and extends that period by six months from the date the carrier gives written notice disallowing a claim that was filed in time. Get every disallowance in writing; the extension depends on it. Rail overcharge claims run three years under 49 USC 11705.

One practical consequence that most shippers miss: because the 180 days runs from receipt of each bill, there is always a rolling six months of paid invoices that are still open to dispute. A shipper who has never audited does not have zero recoverable history. They have 180 days of it, today, and it shrinks by a day every day.

Event	Date	Clock
Shipment delivered (claim accrues)	February 26, 2026	18-month suit clock starts (49 USC 14705)
Invoice received, $4,180 overcharge on a reclass with no certificate	March 2, 2026	180-day contest clock starts (49 USC 13710)
Last day to contest the bill	August 29, 2026	Dispute filed in writing with the BOL and a request for the inspection certificate
Carrier disallows in writing	September 15, 2026	Suit deadline extends six months from this notice
Last day to file suit	August 26, 2027, or later by the extension	In practice, the carrier settles when the certificate does not exist

Parcel is different. UPS and FedEx Ground are motor carriers, but nearly everything about a parcel account is governed by the service guide and your agreement, and both set shorter windows for many charges, including 15 days for guaranteed service refunds. Read the guide before relying on the statute. Dates and statutes on this page are general information, not legal advice; confirm any deadline you are relying on with counsel.

“Every shipper I have ever met has 180 days of recoverable invoices sitting in AP right now. The ones who never audit don't have less exposure. They have the same exposure and a shorter memory.” — Rob Eller

Worked example: $18M program, first audit, $340K found in the open window

A regional food distributor with $18M in annual LTL and truckload spend and no prior audit asks for a first look at the 180 days of invoices still inside the dispute window: about 9,000 invoices, $9M.

Reclassifications without an inspection certificate: 212 invoices, average $186 over the BOL class rate. $39,400.
Accessorials with no BOL or delivery-receipt support: 890 lines, mostly liftgate and residential on commercial addresses with docks. $81,200.
Duplicate invoices: 27, including 14 balance-due bills paid alongside the original. $16,900.
Fuel surcharge on accessorials and on the wrong week: systematic across two of four carriers. $61,800.
Tariff base drift on one carrier after a January general rate increase: every shipment for five months, net linehaul up 5.4 percent with no contract amendment. $127,300.
Late balance-due bills, past 180 days: 19, paid. $6,100.
Minimum charge above contract: 340 shipments. $8,200.

Total disputable: $340,900, or 3.8 percent of the window. The tariff base drift alone was more than a third of it and had not been visible on any individual invoice. Recovery ran about 78 percent, $266,000, with the base drift settled in full once the contract exhibit was put beside the invoices. Going forward, the same errors on the full $18M run at roughly $680K a year in exposure, most of which disappears once the contract fixes below are made.

What your contract should say

Three clauses. They do not stop the errors; they make the errors disputable and the disputes winnable.

Dispute window clause

“Shipper may dispute any charge within 365 days of receipt of the invoice. Carrier shall respond in writing within 30 days of a dispute. Carrier shall not offset disputed amounts against other invoices or withhold service while a dispute is pending, and shall not forfeit any discount on account of a timely dispute of a portion of an invoice.” Longer than the statutory 180, a response deadline, no offsets, and the discount protected.

Supplemental billing clause

“Any supplemental or balance-due invoice shall reference the original PRO number and invoice, shall state only the incremental amount, and shall be accompanied by the inspection certificate, scale ticket, or delivery document supporting the additional charge. No supplemental invoice shall be issued more than 180 days after the original.” This clause alone prevents most duplicate billing.

Documentation clause

“No accessorial charge shall be billed unless the service is noted on the bill of lading or the signed delivery receipt. No reclassification or reweigh shall be billed without an inspection certificate or certified scale ticket furnished with the invoice.” The evidence requirement moves to the carrier, where it belongs.

What to ask your carrier

“Send the inspection certificate or scale ticket for this reclass or reweigh, with the date and location.”
“What is the original PRO and invoice number for this balance-due bill, and when was the original received?”
“Which tariff base and effective date is this rated on, and where does my contract authorize that version?”
“What document shows this liftgate or residential delivery was requested or required?”
“Confirm in writing that disputed amounts will not be offset and that the discount is preserved on the undisputed portion.”

What we can't tell from the bill alone

An invoice shows what was billed. It does not show whether the reclass was measured, whether the consignee had a dock, whether the original bill was already paid, or which tariff version the discount came off. Every error on the list above is settled by a document the invoice does not carry: the BOL, the delivery receipt, the inspection certificate, the scale ticket, the contract exhibit, or the payment record. An audit that runs on invoices alone can flag; it cannot dispute.

Some charges that look like errors are not. A reclass supported by a certificate with measured dimensions is usually right. A liftgate on a delivery receipt signed by the consignee is usually right. The audit's job is to say so, and to tell you which of your own processes produced the charge, because that is the only way the number goes down next year.

How Eller Audit handles this

We start with the invoices still inside the 180-day window, because those are the ones that can still be recovered, and run every line against the signed contract, the fuel index for the pickup week, the carrier's accessorial tariff in force, and the BOL. Duplicates are matched on ship date, origin, destination, and weight across all carriers, not on PRO number. Late balance-due bills are flagged by date against the original. Every finding comes back sorted by the nine freight billing errors above, with the error type, the contract clause, the math, and the dispute drafted, filed within the window with the evidence attached. Performance-based: 15 percent of what is recovered, nothing on lines that hold up. The first audit is free, and it should start with the oldest invoices in the window, because those expire first.

Frequently asked questions

What is the most common freight billing error?

By count, fuel surcharge errors: the wrong index week or the wrong base, on a line that is recalculated for every shipment. By dollars, reclassification and unauthorized accessorials on LTL, and dimensional weight adjustments on parcel. Duplicate billing is less frequent than either but is the most expensive single error when it happens, because the loss is the whole invoice rather than a percentage of it.

How long do I have to dispute a freight bill?

For interstate motor carriers (LTL, truckload, and the ground networks of UPS and FedEx), 49 USC 13710 preserves your right to contest a bill if you do so within 180 days of receiving it. A civil action to recover an overcharge must be filed within 18 months under 49 USC 14705, extended by six months if the carrier disallows a timely claim in writing. Rail overcharge claims run three years under 49 USC 11705. Parcel service guides set their own shorter windows for many charges, including 15 days for guaranteed service refunds, and those windows apply to the contract even where the statute would give you longer.

What is a duplicate freight bill?

Any second invoice for a shipment that has already been billed. It takes several forms: the same PRO number billed twice; a balance-due bill issued after a reweigh or reclass while the original invoice remains open; a shipment rebilled under a new PRO after a correction; the same shipment billed to both the shipper and a third party; or an EDI 210 transmitted twice. Matching on PRO number alone catches only the first form. Matching on ship date, origin, destination, and weight catches the rest.

Can a carrier bill me additional charges after 180 days?

Under 49 USC 13710(a)(3)(A), an interstate motor carrier must issue any bill for charges in addition to those originally billed within 180 days of your receipt of the original bill in order to have the right to collect them. A balance-due bill for a reweigh or reclass that arrives on day 200 is not collectible, and paying it is a voluntary payment. This is one of the more common recoveries on programs that never checked the date.

Do I have to pay a disputed freight bill?

Read your contract first: many carrier agreements require payment of undisputed portions within terms and allow the disputed portion to be withheld pending resolution, and some tariffs forfeit your discount if the whole invoice is not paid within 30 days. The practical approach is to pay the undisputed amount on time, dispute the balance in writing within the 180-day window with the evidence attached, and document that the carrier received the dispute. Never let a disputed invoice age unpaid in full; a forfeited discount can cost more than the line you were disputing.