What is Three-Way Matching?

Three-way matching is a fundamental accounts payable control. The concept is simple: before you pay a supplier, you verify that what was ordered (purchase order), what arrived (delivery receipt), and what is being charged (invoice) all tell the same story. If they do, you pay. If they do not, you investigate first.

The three documents each serve a distinct purpose. The purchase order records what was agreed: item descriptions, quantities, unit prices, and delivery terms. The delivery receipt or goods received note confirms what physically arrived at your premises, including quantities and condition. The invoice is the supplier's request for payment. A valid match means the invoice charges only for items that were both ordered and received, at the prices originally agreed.

Mismatches are common and fall into predictable categories. Partial deliveries are the most frequent: the supplier ships 80 of 100 units but invoices for 100. Price discrepancies occur when the invoice reflects a different rate than the purchase order, sometimes due to a legitimate price change that was not updated in the contract, sometimes due to error. Quantity errors, duplicate invoices, and charges for items never ordered also surface regularly during the matching process.

Despite its simplicity, most small and mid-sized businesses do not perform three-way matching consistently. Invoices arrive, get approved by someone who may not have seen the purchase order or the delivery receipt, and are paid. The disconnect between procurement, warehouse, and finance teams means nobody has the full picture.

The fix does not require expensive software. At its most basic, three-way matching means keeping purchase orders on file, requiring delivery receipts to be signed and stored centrally, and checking both documents against each invoice before authorising payment. For businesses processing dozens of invoices monthly, a simple spreadsheet tracking PO number, delivery confirmation, and invoice number is sufficient to start.

CIPS research indicates that 80 percent of invoices do not match the underlying contract terms. That figure covers everything from minor unit price differences to charges for goods that were never delivered. Without a matching process, these discrepancies go undetected and the business overpays.

The problem is compounded by human error. Ironclad's 2025 analysis found that 92 percent of contract management errors are attributable to manual mistakes. When invoice approval relies on a single person scanning the total and clicking "approve," errors pass through unchallenged. Three-way matching introduces a second and third checkpoint that catches what individual review misses.

For SMEs, the payoff is immediate. Even checking a sample of ten invoices per month against their purchase orders and delivery receipts will typically reveal at least one discrepancy worth correcting.