Purchase order matching is a control in the purchasing and payment cycle in which each supplier invoice is checked against the purchase order the buyer issued. The check confirms that the supplier, items, quantities, unit prices and terms on the invoice agree with what was ordered and approved. Invoices that agree within set tolerances are passed for payment; those that do not are held and referred to the buyer or supplier for resolution.
Comparing the invoice with the order alone is known as two-way matching. Adding the record that the goods actually arrived gives three-way matching, which is the usual standard for physical goods. Matching protects against overbilling, duplicate invoices and payment for unauthorised purchases, and it is a core defence against invoice fraud. In modern accounts payable systems it is performed automatically, with staff handling only the exceptions. It forms part of wider invoice matching.