What Is 3-Way Matching?
3-way matching is the process of comparing three documents before approving an invoice for payment:
- Purchase Order (PO) — What you agreed to buy, at what price
- Goods Receipt Note (GRN) — What you actually received
- Vendor Invoice — What the vendor is billing you for
- Goods or services you didn't order
- Quantities greater than what you received
- Prices higher than what was agreed
Why 3-Way Matching Matters
Prevents Overpayments
Without matching, vendors occasionally invoice for more than the agreed price or for undelivered quantities. Automated matching catches these discrepancies immediately.Reduces Fraud
3-way matching is one of the most effective controls against invoice fraud — both external (fraudulent vendor invoices) and internal (fictitious purchase schemes).Accelerates Payments
When matching is manual, invoices sit in queues waiting for someone to cross-reference documents. Automated matching processes matched invoices instantly, enabling early payment discounts.Simplifies Audits
Every payment has a complete matching audit trail — PO reference, GRN reference, matching result, and approval decision.The 3 Documents Explained
Purchase Order (PO)
The PO is issued by your procurement team when a purchase is authorised. It specifies:- Supplier name and GSTIN
- Item descriptions and HSN codes
- Ordered quantities
- Agreed unit prices
- Delivery terms and expected date
- Payment terms
Goods Receipt Note (GRN)
The GRN is created by your warehouse or receiving team when goods arrive. It records:- PO reference number
- Items received
- Quantities received (may differ from ordered)
- Condition of goods (accepted/rejected)
- Receipt date
Vendor Invoice
The invoice is sent by the supplier requesting payment. It should match the PO and GRN for:- Item descriptions and HSN codes
- Quantities billed (should not exceed GRN quantities)
- Unit prices (should match PO prices)
- Tax calculations
Common 3-Way Matching Discrepancies
Price Variance
Vendor invoices at a higher price than the agreed PO price. This may be due to:- Price increase without amended PO
- Different unit of measurement
- Currency conversion error
- Deliberate overcharging
Quantity Variance
Invoice for more units than received on the GRN. This may be due to:- Partial delivery not yet reflected
- Counting error at receiving
- Backorder being invoiced before delivery
- Deliberate overbilling
Description Mismatch
Invoice line items don't match PO descriptions. May indicate:- Wrong item delivered
- Substitution without approval
- Code or SKU mismatch
Where TaskAutomate Fits Today
TaskAutomate doesn't do PO and GRN matching yet. It handles the invoice side of the process:
- Extracts line items, quantities, unit prices, tax and totals from vendor invoices
- Checks GSTINs and the CGST/SGST/IGST split
- Holds every invoice for approval, with an amount threshold above which approval is required
- Posts approved invoices to Tally, or exports them to CSV and Excel for matching in your ERP