Price discrepancies
Supplier invoice price discrepancies: find them, then get them back
Most off-contract billing is small, routine and invisible on a single invoice. Here is where it comes from, how to detect it across thousands of lines, and the process that converts a finding into a credit.
Related reading: the unmatched-line taxonomy, the audit checklist, and what to do when a supplier won't credit you.
What counts as a price discrepancy
A price discrepancy is any line where the unit price billed differs from the contracted price in effect on the invoice date. That last clause does most of the work. A line billed at last quarter's agreed price is not a discrepancy; a line billed at list because a price list quietly expired is, even though nothing about the invoice looks unusual.
Where they come from
- A price list expires and the supplier's system reverts to list pricing until someone loads the renewal.
- A job-specific quote follows a SKU onto unrelated projects, or stops applying to the job it was written for.
- A part number changes and the replacement was never added to the agreement.
- The unit of measure on the invoice differs from the unit the contract was priced in.
- A branch bills from a regional price file that was never updated with your national agreement.
- A credit is issued without the matching rebill, or the rebill lands at the wrong price.
Why they survive normal controls
Accounts payable checks that the invoice is arithmetically correct, matches a purchase order, and has not been paid before. None of those compares unit price to the contract in force on the invoice date. The three-way match is a quantity control, not a price control, and the purchase order price is often keyed from the same quote you would be auditing.
Finding them at scale
- Load the price lists with their effective dates, not just the current version.
- Normalize units of measure on both sides before comparing anything.
- Stem part numbers so distributor-specific variants match the contracted item.
- Pair credits with their rebills so one correction is not counted as two events.
- Set a percentage and a dollar tolerance so rounding noise stays out of the work queue.
- Classify every unmatched line by reason, so the exceptions become a to-do list instead of a pile.
Turning a finding into money
A discrepancy report is not recovery. Group the lines by supplier and period, attach the contract version and the invoice reference to each, and submit one documented claim rather than a stream of individual complaints. Track each claim through submitted, disputed, credited or written off, with an owner and a date. Suppliers settle documented batches; they argue with unevidenced emails.
How much is usually there
On spend governed by contracted price lists, an error rate of roughly one to two percent of line value is a conservative planning assumption, of which a documented, in-window portion is realistically recoverable. Run your own numbers before you take anyone's word for it — including ours.
Common questions
- How far back can we claim a price discrepancy?
- That depends on your supplier agreement and local limitation periods. Many agreements are silent, in which case practice governs: suppliers commonly credit the current and prior quarter without argument and negotiate anything older. Documented, itemized claims get much further back than general complaints.
- Is this the same as duplicate payment auditing?
- No. Duplicate payment auditing catches the same invoice paid twice. Price discrepancy auditing catches a wrong price billed once, which is far more common and much harder to see.
- Do we need clean data to start?
- No. Messy exports are the normal case. Saved column-mapping profiles per supplier absorb odd layouts, header rows in the wrong place, and unit spellings that differ file to file.
- What about undercharges?
- They are reported separately and classified as standing, quoted or isolated. A standing discount is your real price and belongs in the next renewal; a quoted discount that outlived its job is a clawback waiting to happen.
See your own numbers
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