Which rules does it run?

Rule	Invoices	Question it writes
Fuel or energy surcharge	Hauling, Freight	Which published index and which table does this surcharge follow, and which week’s price was used on this invoice? Where in our contract is it allowed?
Environmental, recovery or admin fee	Hauling, Freight	What cost does this fee recover, how is the amount set, and which clause of our agreement allows it? Can it be removed or capped at renewal?
Container or equipment rental billed separately	Hauling	Is container rental a separate agreed charge in our contract, or part of the service rate? What is the monthly rate per container, and which containers is it for?
Contamination charge	Hauling	Please send the dated photo and the pickup record for this charge, and the contamination policy in our agreement.
Extra pickup or overage	Hauling	Please send the dated service tickets or driver photos for each extra pickup or overage on this invoice.
Disposal by weight	Hauling	Please send the scale tickets for these tons, with dates and the disposal site.
Trip, dry-run or delivery charge	Hauling	What date was this, what was the reason recorded by the driver, and is there a photo?
Container access charge	Hauling	Is this service in our contract rate? How often is it billed, and can it be removed if we place the container for the driver?
Liftgate accessorial	Freight	Was a liftgate requested on the bill of lading? Our location has a dock: can this be reversed?
Residential delivery charge	Freight	This address is a business. What made it residential, and can the charge be reversed and the address corrected in your system?
Reweigh or re-class	Freight	Please send the inspection certificate or reweigh ticket, with photos and the dimensions you measured. What weight, dimensions and class did you record?
Dimensional weight, size or handling charge	Freight	What dimensions were recorded for this package? Please send the scan or measurement.
Detention, waiting or loading help	Freight	What were the arrival and departure times recorded, and what free time applies under our agreement?
Redelivery, storage or address correction	Freight	What caused the failed attempt or correction, and what address or appointment detail was missing?
Delivery-condition accessorial	Freight	Was this service requested on the bill of lading or by the consignee? If not, please reverse it.
Delivery area surcharge	Freight	Which ZIP list applied to this delivery, and does our agreement discount delivery-area surcharges?
Billing fee	Hauling, Freight	Is this fee in our agreement? Will it be waived if we move to e-invoicing or ACH?
Price change line	Hauling, Freight	Which clause and which index allow this increase, and when was written notice sent?
Possible duplicate line	Hauling, Freight	Are these two separate services, and on which dates?

Why no refund amount?

Because the invoice alone can’t prove one. Whether a fee is allowed depends on your contract; whether a liftgate was needed depends on your dock. The check finds the lines worth asking about. An audit reads the contract and evidence behind them.