Three-Way Match: PO, GRN and Invoice

Three documents, three different questions

A three-way match is not redundant paperwork. Each of the three documents answers a genuinely different question, and only all three together prove a payment is actually justified.

• —The Purchase Order proves what was agreed and at what price: your own authorised commitment, made before anything shipped.
• —The Goods Receipt Note (GRN) proves what was actually physically received, confirmed by whoever took delivery — independent of what was ordered or billed.
• —The supplier invoice proves what is being billed.

Three different people typically create these three documents, at three different points in time. The match is simply checking whether all three agree.

The three mismatches that actually cost money

Each possible mismatch means something specific and concrete:

• —Quantity. PO says 100 units, GRN says 95 arrived, invoice bills 100. You are being billed for five units you never received.
• —Price. PO price was ₹500 per unit, invoice bills ₹550. A discrepancy from what was actually agreed.
• —Condition. GRN notes a batch damaged on arrival; the invoice bills the full amount with no adjustment.

Every one of these is a real reason the invoice should not be approved for payment as submitted.

The correct response to a mismatch

Do not approve the invoice as-is, and do not split the difference to make it close enough. Hold the invoice, raise a formal query with the supplier referencing the specific discrepancy, and release payment only once it is resolved — either the supplier corrects the invoice, or you confirm your own GRN was wrong and correct that instead.

The temptation to “just pay it and sort it later” is exactly how small, repeated overbillings become permanent. Once paid, recovery depends entirely on the supplier’s goodwill.

When the three-way match does not apply

It fits goods purchases cleanly, and only goods purchases. A utility bill has no PO and no GRN — nothing was ordered or physically received in that sense. A professional-fee invoice has no goods receipt either.

The control there is different, not absent. Verify a utility bill against the actual meter reading or billing period, and against the prior month for a reasonableness check. Verify a professional-fee invoice against the engagement terms. Applying the three-way match literally where it does not fit usually means the bill never gets a real check at all — the form is satisfied and the substance is missed.

Why this control earns its emphasis

It is genuinely cheap to run: it compares three documents someone already has to produce anyway. And it closes off several of the most common ways money actually leaks out of a business — billing for goods never delivered, inflated quantities, and prices quietly different from what was agreed. Very few controls deliver that much protection for that little ongoing effort.

Segregation of duties is what makes it real

The person who raises the PO, the person who confirms the GRN, and the person who approves the invoice for payment should not all be the same person. If one individual controls the whole chain, a fabricated PO, a fabricated GRN and an approved payment to a fake or complicit supplier can all be created by that one person, with nothing independent checking any of it.

Splitting these three steps across different people is a structural fraud deterrent, not a formality. A three-way match performed start to finish by one person is documentation, not a control.

Common mistakes

• —Approving an invoice because the total looks about right, without comparing line quantities.
• —Treating the GRN as a formality signed on trust rather than an actual count on receipt.
• —Forcing non-goods suppliers through a match that cannot apply, so they get no check at all.
• —One person owning the PO, the GRN and the payment approval.