Carrier invoice audit calculator
Rebuild what a freight invoice should say from the contract: the linehaul rate, the fuel surcharge percentage and the accessorials you ordered, then compare it line by line with what the carrier invoiced. The variance and a list of flags come out, the way a freight auditor reads the bill.
You checked one charge. Mirage checks every carrier invoice.
Every carrier invoice checked against the contracted rate and the shipment record before payment: detention, demurrage and accessorial overcharges caught. Send us a few invoices and we send back a plan, no commitment.
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How to use it
- Take the rate from the contract or rate confirmation for this lane, and the fuel percentage from the carrier's fuel table for the week of pickup.
- Enter the accessorials you actually ordered and their contracted prices, and the time the truck spent at the stop from the POD or the ELD.
- Copy the invoice line by line: linehaul, fuel, detention, each accessorial, anything else, and the total.
- Read the variance and the flags. A flag is a question for the carrier, not a verdict: the answer is in the rate confirmation, the POD and the fuel table.
- Short-pay or dispute only what the documents support, and log the result so the same error does not pass next week.
What is rebuilt and how
fuel surcharge = linehaul × fuel %
detention = max(0, hours at stop − free time) × hourly rate
accessorial = contracted charge, when the service was ordered, else 0
expected total = linehaul + fuel + detention + accessorials
variance = invoiced total − expected total
Every expected line comes from a document you hold: the rate confirmation, the fuel table and the order. The invoice is compared to those documents, never to a guess. The flags are the checks an auditor runs on each line, and each one names the document that settles it.
The common overcharges
- Wrong rate
- An old rate table, a different weight break or a mileage program the contract does not use. The most frequent and the easiest to prove.
- Fuel on everything
- The fuel percentage applied to the invoice total instead of linehaul. On an invoice with accessorials it adds a few percent nobody notices.
- Detention without the clock
- Hours invoiced that the POD does not support, or free time ignored. Arrival and release times decide it.
- Accessorials not ordered
- Liftgate, residential, inside delivery or redelivery charged by default because the address or the consignee type looked like it. The order says what was requested.
- Duplicates and unexplained lines
- The same shipment invoiced twice under two numbers, or a line labelled 'other' or 'misc'. Each needs a document before it is paid.
A worked example
A lane contracted at 1,200 with 22% fuel, free time 2 hours then 75 per hour, liftgate at 45. The truck waited 3 hours. Expected: 1,200 + 264 + 75 + 45 = 1,584. The invoice says linehaul 1,200, fuel 303.60, detention 75, liftgate 45, residential 60, total 1,700. Flags: the fuel equals 22% of 1,380, so the percentage was applied to the accessorials too (39.60 too much); a residential charge on a commercial address; and a total 16.40 above the sum of its own lines. Variance: 116 on one invoice.
FAQ
What is a freight invoice audit?
Checking each carrier invoice against the contract before paying it: the rate for the lane, the fuel surcharge for the week, the accessorials ordered and the times recorded on the delivery documents. Anything the documents do not support is questioned, short-paid or disputed.
What is a fuel surcharge and what should it apply to?
A percentage added to the linehaul rate that follows the price of diesel, read from the carrier's fuel table for the week of pickup. It normally applies to linehaul only, not to detention, liftgate or other accessorials, unless the contract says otherwise.
How is detention calculated?
The time the truck spent at the stop, minus the free time the contract grants (often two hours), times the hourly rate. The arrival and release times on the proof of delivery or the driver's log are the evidence; without them, the charge is only a claim.
What are accessorial charges?
Charges for services beyond moving the freight: liftgate, residential delivery, inside delivery, redelivery, limited access, detention, layover. Each should be in the contract with a price and should appear on the invoice only when the service was ordered or recorded on the delivery documents.
Should I audit every invoice or a sample?
Every invoice, if you can: the errors are small per invoice and frequent, so a sample under-counts them. That is why most teams either automate the comparison or outsource it to a freight audit provider paid on recovered amounts.
The audit is only as good as the three documents behind it.
Mirage deploys AI agents that read the carrier invoice, the rate confirmation and the proof of delivery, rebuild the expected charges and flag the differences before payment, for your team to decide on.
See freight invoice audit automation