What is 3-way matching?

3-way matching is an accounts payable control that verifies an incoming invoice against the original purchase order (PO) and the goods receipt note (GRN) before approving payment — preventing over-payment, duplicate payment and fraud.

The three documents

Each document represents a different stage of the procure-to-pay cycle and is raised by a different party:

Why 3-way matching matters

Without 3-way matching, AP teams pay invoices without verifying that the goods were ordered and received. The control protects against:

• Over-billing — supplier invoices more units or higher prices than agreed.
• Phantom deliveries — invoices for goods never received.
• Duplicate payments — the same invoice paid twice.
• Internal fraud — fake invoices slipped into the AP queue.
• Audit exposure — auditors expect a documented control with an evidence trail.

Step-by-step process

1. 1. Retrieve the PO

   Use the PO number referenced on the invoice to pull the original order from the ERP or procurement system.

2. 2. Retrieve the GRN

   Pull the goods receipt note for the same PO from the warehouse system.

3. 3. Compare line items

   Check each line: SKU, quantity and unit price must agree across all three documents (within tolerance).

4. 4. Flag exceptions

   Mismatches are routed to AP or procurement for resolution — partial delivery, price dispute, missing PO.

5. 5. Approve for payment

   Matched invoices proceed to payment; unmatched ones are held until resolved.

Manual vs automated 3-way matching

Related terms

• Accounts payable automation — the broader workflow in which 3-way matching sits.
• Invoice data entry — the capture step that produces the structured invoice used for matching.
• OCR — the technology that extracts PO numbers and line items from invoice PDFs.