Three-way matching is an internal control process of comparing three procurement documents before a payment is made to prevent overpayment. There are three critical documents involved in the three-way matching process and they are the purchase order, goods receipt note (GRN), and supplier invoice. The accounts payable team compares these documents against each other to perform the three-way matching process.

When performing three-way matching, the accounts payable team compares the information on the supplier’s invoice against the respective purchase order and goods receipt note (GRN). They ensure that the items, quantities, and prices match between the PO and invoice, while making sure that the invoice and GRN agree with the number of quantities delivered.