A price variance exception is raised when the unit price on a supplier invoice does not match the price on the purchase order or contract, beyond the tolerance the company allows. The invoice fails the price check in three-way matching and is routed to a person to confirm which price is correct.
It is one of the most common exceptions an AP team sees, and most price variances turn out to be small.
The control exists to catch overbilling
During matching, the system compares the invoiced unit price against the price recorded on the purchase order. If the two differ by more than the allowed tolerance, the line is flagged. A variance can go either way. An overbill, where the supplier charges more than agreed, is the case the control exists to catch. An underbill is less urgent but still stops the automated match.
Most price variances trace to stale purchase orders
Most price variances are not error or fraud. A price was renegotiated after the purchase order was cut, so the invoice is right and the order is stale. A contract has tiered or volume pricing the order did not reflect. A currency conversion moved between order and invoice. A supplier applied a surcharge or a rounding convention the buyer did not expect. Each of these produces a real gap that a person has to explain.
Tolerances decide what reaches a person
Whether a variance becomes an exception depends on the tolerance. A tolerance is the gap the company will accept without review, set as a fixed amount, a percentage of the line, or both. Set it tight and the queue fills with cent-level differences that are not worth a person's time. Set it loose and genuine overbilling clears without a look. Most companies tune tolerances by category and supplier over time.
The investigation costs more than the variance
The clerk opens the invoice, pulls the purchase order, and looks for the source of the gap. If the contract shows the new price, they update the order or approve the variance. If it does not, they email the buyer or the supplier and wait for confirmation. On high-volume, low-value lines this investigation costs far more than the variance itself, which is why price exceptions are a frequent target for automation.
Prevention has a ceiling; resolution is the real lever
Prevention helps: keeping contract prices synchronized with purchase orders, updating orders when prices change, and setting tolerances that match how a category actually prices. It does not remove the cause entirely, because prices move for reasons outside AP. That leaves resolution, where a system that can read the contract and the pricing history can confirm most variances without a person.
Fragment clears price variance exceptions on its own by reading the purchase order, the contract, and the supplier's pricing history in place. See how it works or request a demo.