Three-way match: how to check invoices against purchase orders and receipts

Paying an invoice is easy. Paying the right amount for the right goods, once, is the hard part. Three-way matching is the standard control that makes sure of it. Before any payment is released, three documents must agree.

The three documents

1. Purchase order (PO). What you agreed to buy: item, quantity, price and terms.
2. Goods receipt, or service acceptance. What actually arrived and was accepted.
3. Supplier invoice. What the supplier is asking you to pay.

The match checks that the invoice does not charge for more than was ordered, more than was received, or at a different price than agreed.

What is compared

A clean match means the quantity billed is no more than the quantity received, and the price equals the PO price within tolerance. Then the invoice can be approved for payment.

Two-way, three-way and four-way

• Two-way match compares the PO and the invoice only. It is faster but cannot tell whether the goods arrived. It suits low-risk, low-value or service purchases.
• Three-way match adds the receipt. It is the common standard for goods.
• Four-way match adds an inspection or quality result, so that only accepted goods are paid.

Choose the level by risk and value. A tiny recurring subscription does not need the same checks as a large equipment order.

Set tolerances

Real life is never exact. Rounding, small freight differences and part deliveries are normal. Define tolerances in advance, for example:

• Price tolerance. An invoice up to a small percentage or amount above the PO may pass automatically. Anything beyond goes to review.
• Quantity tolerance. Allow for small over-delivery on bulk goods if your policy permits it.
• Hard stops. An invoice above the order value, or for goods not received, is blocked until someone with authority resolves it.

The exact numbers belong to your policy. What matters is that they are written down and applied the same way to every supplier.

Handling mismatches

When the three documents disagree, find out which one is wrong before anyone pays.

• Invoice above the PO price. Ask the supplier for a corrected invoice or a credit note, or get an approved PO amendment if the higher price was genuinely agreed.
• Invoice for more than was received. Pay only for what was received, or hold the invoice until the rest arrives.
• Goods received but no invoice. Record the receipt anyway so you know what you owe.
• Duplicate invoice. Check the supplier and invoice number against past invoices before paying.
• Rejected goods. Record the rejection and do not pay for them. Ask for replacement or a credit.

Keep a short note of the reason for each exception. It builds a picture of which suppliers or categories cause the most errors.

Why it matters

• Prevents overpayment and duplicate payment. The most common leaks in accounts payable.
• Reduces fraud risk. A fake invoice has no matching order or receipt.
• Supports audit. Each payment has a documented basis.
• Improves supplier relations. Clear rules and quick resolution of disputes.

Making it easier with software

Doing this by hand across hundreds of invoices is slow. An eProcurement system holds the PO, the delivery record and the invoice together, so the comparison can be shown on one screen and flagged where it fails. Receiving the invoice as structured data, as described in E-invoicing: closing the loop from order to payment, makes automatic matching much more reliable than keying in a PDF.

In the eProcurement.si buyer workspace the steps run in order: purchase order, delivery, inspection, invoice, payment record, and closing. Read the full sequence in The complete procurement lifecycle.

A quick start

1. Decide which purchases need two-way, three-way or four-way matching.
2. Write tolerances and a rule for who approves exceptions.
3. Make sure every invoice quotes a PO number.
4. Record receipts promptly, on the day goods arrive.
5. Review exceptions monthly and fix the causes.