What is invoice matching?

‍

Invoice matching is the process of comparing a supplier invoice against one or more reference documents to verify that the invoice is accurate and should be paid. The reference documents typically include a purchase order (PO) and a goods receipt note (GRN) — the record confirming that goods or services were actually received.

‍

It is a core control in the procure-to-pay process and the primary mechanism for preventing overpayments, duplicate payments, and fraudulent invoices.

‍

Two-way vs three-way matching

‍

Two-way matching compares the invoice against the purchase order: does the amount, quantity, and supplier on the invoice match what was ordered? This is used for service-based purchases where there is no physical goods receipt.

‍

Three-way matching adds the goods receipt to the comparison: the invoice must match both the PO and the confirmation that goods were actually received. This is standard for goods-based purchasing and provides a stronger control, since it prevents payment for goods that were ordered but never delivered.

‍

Why it breaks

‍

Invoice matching fails — and becomes a source of cost and delay — when POs are raised after the invoice (maverick buying), when invoice formats vary and can't be parsed reliably, when the GRN is recorded with a different quantity or unit than the invoice, or when partial deliveries mean the invoice covers only part of a PO.

‍

Automated invoice matching handles format variation through OCR and AI-based extraction, applies matching rules consistently, and routes exceptions to the right owner with context attached — rather than bouncing them back and forth between AP and procurement.

‍

Related: Three-Way Matching · AP Automation · Procure-to-Pay (P2P) · Purchase Order