Three-way matching: checking the purchase order, the goods receipt and the invoice before you pay
Before an organisation pays a supplier, someone should be able to answer three questions: did we order this, did we receive it, and is the supplier asking for the price we agreed? Three-way matching answers all three by comparing the purchase order, the goods receipt and the invoice. It is one of the oldest controls in purchasing, and one of the most common reasons suppliers get paid late. This guide explains how it works, where it breaks, and how buyers can make it a control rather than a bottleneck.
The three documents
Matching sits near the end of the purchase-to-pay cycle described in our guide to the procurement process. Each document comes from a different party, which is exactly what makes the comparison useful:
- The purchase order (PO) is raised by the buyer. It records what was ordered, in what quantity, at what unit price, on which terms and for which cost centre.
- The goods receipt (or service entry, for services) is recorded by whoever took delivery or confirmed the work. It records what actually arrived and when.
- The invoice comes from the supplier. It states what the supplier says it delivered and what it wants to be paid.
Because the requester, the receiver and the supplier each produce one piece of the evidence, no single person can create and approve a payment on their own. That separation of duties is the real purpose of the match; catching honest errors is a welcome side effect.
What gets compared
| Check | Compared between | What a mismatch usually means |
|---|---|---|
| Supplier and PO reference | PO and invoice | Invoice sent without a PO number, or to the wrong entity |
| Item or service line | All three | Substitute product, or a line description that differs from the catalogue |
| Quantity | Receipt and invoice (and PO) | Partial delivery invoiced in full, over-delivery, or receipt not yet booked |
| Unit price | PO and invoice | Price increase not agreed, or a price change agreed but not updated on the PO |
| Terms, freight, taxes | PO, contract and invoice | Delivery charges added, different payment terms, wrong tax treatment |
A two-way match compares only the PO and the invoice. It is common for services, subscriptions and low-value items where there is no physical delivery to book. A four-way match adds a fourth document, usually an inspection or acceptance record, for goods that must pass quality control before they count as received.
What a public-sector rulebook requires
Private companies set their own matching rules, but public bodies often have them written down, and those rules are a useful benchmark. In the United States, the federal Prompt Payment regulations (5 CFR Part 1315) list what a "proper invoice" must contain: the vendor's name, the invoice date, the contract number or other authorisation, an invoice number, a description, price and quantity of the goods or services, shipping and payment terms, and contact details, among other items. They separately list what a receiving report must show, including quantities received, delivery dates and acceptance dates, and the receiving official's signature or an electronic equivalent.
The same regulation shows the other side of the control. An agency that finds an invoice improper must return it no later than seven days after receipt, identifying every defect that prevents payment. And where an agency uses a fast-payment procedure that pays before receipt is verified, it must still ensure that receiving reports and payment documents are matched afterwards and discrepancies corrected. In other words: matching is mandatory, but so is telling the supplier quickly and completely what is wrong.
Tolerances: how exact is exact?
Insisting on a perfect match for every line creates huge exception queues over rounding differences and small freight variations. Most finance systems therefore let buyers set tolerances, as a percentage, an absolute amount or both, beyond which an invoice is blocked. There is no universal correct value; it is a policy decision that should reflect risk:
- Tight or zero tolerance on unit price for contracted items, because an accepted price creep is hard to reverse.
- A small quantity tolerance for goods sold by weight or length, where deliveries rarely hit the ordered figure exactly.
- Separate rules for freight and surcharges, which the contract should say whether the supplier may add.
- Regular review of what is being paid within tolerance, so that small variances do not quietly add up.
Why invoices get stuck
In practice, most blocked invoices are not attempted fraud. They are process gaps on the buyer's side as often as the supplier's:
- Receipt not booked. The goods are on the shelf but nobody recorded them, so the invoice waits for a receipt that will never come unless someone chases it.
- PO raised after the invoice. A "retrospective" PO matches on paper but defeats the purpose of the control, and it is a sign that buying is happening outside the process.
- Price changed in the contract, not on the PO. A price review agreed under the contract must reach the open orders too. Our guide to contract management after signature covers how changes should be recorded.
- Missing or wrong PO number on the invoice. Suppliers should be told, in the order itself, that invoices without a valid PO reference will be returned.
- Partial deliveries. A supplier invoices the full order while only part has arrived; the system should match line by line against what was actually received.
Each exception needs an owner and a deadline. An invoice that sits in a queue for weeks can push the buyer past the payment terms it agreed, and in several jurisdictions late payment triggers statutory interest. Our guide to supplier payment terms explains the legal limits and why a payment term only works if the buyer's own process can meet it.
Alternatives that keep the control
Matching every invoice line by hand does not scale. Organisations reduce the workload without dropping the control in a few ways:
- Evaluated receipt settlement (ERS). For stable, contracted supplies, the buyer pays on the basis of the goods receipt and the contract price, without waiting for an invoice. The US regulation above explicitly lists "evaluated receipts" among the documents that can support payment. ERS needs clean master data and a supplier who agrees to it.
- Purchasing cards for low-value, one-off purchases, with monthly review of the statement instead of matching each transaction.
- Framework orders and blanket POs with call-offs, so that repeat purchases match against an agreed price list rather than a new order every time.
- Electronic invoicing and automatic matching. When invoices arrive as structured data rather than PDFs, the system can match most lines automatically and send only exceptions to a person. The e-procurement software landscape describes the tools that do this.
A short checklist
- Every purchase above a set value has a PO before the supplier is engaged.
- Receipts and service confirmations are booked when the goods or work arrive, not when the invoice turns up.
- Tolerances are written down, approved by finance and reviewed.
- Price changes agreed in contracts are pushed to open POs.
- Blocked invoices have an owner, a deadline and a reason sent to the supplier.
- Exception reports show which suppliers, buyers and sites cause the most mismatches, so the root cause gets fixed.
Done well, three-way matching protects the organisation's money without punishing its suppliers. Done badly, it becomes the reason good suppliers price in late payment.
Process & toolsThe procurement process
From identifying the need to invoice matching and payment, step by step.
Suppliers & riskSupplier payment terms
Legal maximums in the EU, France and the UK, late payment interest, early payment discounts and fair terms.
Process & toolsE-procurement software
Source-to-pay suites, e-sourcing, contract management and P2P: what each type of tool does.