Two-Way Match

Two-way matching is an accounts payable control that compares a supplier invoice against an approved purchase order before authorising payment. The comparison checks two things: that the invoice is for goods or services that were actually ordered, and that the price and quantity on the invoice match what was agreed in the PO.

It is called two-way because it involves two documents: the purchase order and the invoice. When the two match within an acceptable tolerance, the invoice can proceed to payment without additional manual verification. When they do not match, the invoice becomes an exception that requires human review before it is approved.

What two-way matching checks

A two-way match compares the following fields between the purchase order and the invoice: supplier name, PO number, line-item descriptions, quantities ordered versus quantities invoiced, agreed unit prices versus prices on the invoice, and total invoice value versus total PO value. If all fields match within a defined tolerance, the match is successful. If any field is outside the tolerance, the system flags the invoice for review.

Tolerance levels are set by the business. A common tolerance for price variances is plus or minus two to three percent. Quantity variances are typically expected to match exactly, though some businesses allow for minor differences in weight or volume for commodity purchases. The tolerance setting is a judgment call: too tight and you create unnecessary exceptions; too loose and you allow overcharging to pass undetected.

What two-way matching does not catch

Two-way matching verifies that an invoice corresponds to something that was ordered and at the right price. It does not verify that the goods were actually delivered. This is the critical limitation of two-way matching compared to three-way matching.

A supplier could submit an invoice for an order that was placed but not yet delivered, and a two-way match would pass it. In construction and manufacturing, where goods are delivered in stages and payment should follow confirmed delivery, this gap is significant. Paying for goods not yet received reduces the buyer's leverage in case of a dispute and creates a receivable on the supplier's books that the buyer does not yet have benefit of.

When two-way matching is sufficient

Two-way matching is appropriate for service invoices where there is no physical delivery to confirm, for invoices from highly trusted long-term suppliers where delivery confirmation is not a material risk, and for businesses where the time and system cost of implementing three-way matching outweighs the risk of paying without delivery confirmation.

For most Australian SMBs, two-way matching provides a significant improvement over no matching at all. It eliminates the most common AP failures: invoices for goods never ordered, invoices at prices higher than agreed, and invoices from unknown or unapproved suppliers. Three-way matching adds the delivery confirmation layer, which is most valuable in industries where goods are frequently short-delivered or where high-value inventory is involved.

Two-way matching in AP automation

In a manual AP process, two-way matching requires the bookkeeper or AP clerk to locate the original PO, compare it to the invoice, and document the comparison. At scale, this is time-consuming. AP automation software performs this comparison automatically for every invoice, flagging exceptions for human review rather than requiring manual comparison of every invoice against its PO. The result is that AP staff spend their time on genuine exceptions rather than routine matching work.