Purchase Order, GRN and Invoice Three-Way Matching

• CFO or Finance Controller
• Accounts Payable Manager
• Purchase Head
• Stores and Inward Manager

A plant receives supplier invoices as PDFs, scans and email attachments, often before or after the material is received and inspected. Accounts payable has to tie each invoice line to the PO and to the GRN quantity that quality accepted, then sort out short supply, rejections and price differences before anything is posted.

We build a matching pipeline that reads each supplier invoice, extracts header and line items, and matches them to open PO lines and accepted GRN quantities pulled from SAP or Tally. It handles partial deliveries, several GRNs per invoice and unit-of-measure conversions. Rules check price and quantity against your tolerances, compare GST details with the supplier master and e-invoice data, and flag possible duplicates. Clean invoices are prepared as parked documents or draft vouchers for AP to post. Exceptions go to a queue with a reason code, plus a proposed debit note where quantity was short or rejected.

• Extracts invoice header, line items, HSN codes, tax splits, freight and TDS-relevant fields
• Matches many-to-many across invoice lines, PO lines and GRNs, including unit conversions
• Applies price and quantity tolerances per supplier or material group
• Checks GSTIN, tax rate and place of supply, and reads the e-invoice QR code where present
• Detects duplicate invoices by supplier, number, date and amount, including re-sent scans
• Proposes debit notes for short supply, QC rejections and price differences with evidence attached

1. 01Capture invoicesInvoices arrive from the AP mailbox, a supplier portal or scans at the inward gate and are grouped by supplier.
2. 02Extract and validateOCR and an LLM extract header and line data, each field with a confidence score and page reference.
3. 03Match to PO and GRNLines are matched to open PO lines and accepted GRN quantities from SAP or Tally.
4. 04Apply tolerance and GST checksPrice, quantity, tax and duplicate rules run, and each failure gets a reason code.
5. 05AP review of exceptionsAP sees the invoice, PO and GRN side by side and resolves the exception or escalates it to purchase.
6. 06Prepare for postingMatched invoices are created as parked documents or draft vouchers, with debit note proposals where needed.

1. Intake
   • AP mailbox and supplier portal connectors
   • Scan upload from the inward gate
   • Supplier identification from GSTIN
2. Extraction
   • OCR with table detection
   • LLM extractor with invoice schema
   • E-invoice QR decoder
3. Matching and rules
   • PO and GRN fetch from SAP or Tally
   • Many-to-many line matcher
   • Tolerance, GST and duplicate rules
4. Review
   • AP exception queue with side-by-side view
   • Debit note proposal generator
5. Posting and audit
   • SAP BAPI or IDoc adapter, or Tally XML import
   • Audit log of every match and reviewer change

AP executives resolve every exception and post every invoice; the system prepares documents and never posts or releases payment. Buyers decide price variances, and stores or quality confirm disputed quantities before a debit note is raised.

• SAP S/4HANA or ECC (MM and FI) via BAPI, IDoc or API
• Tally Prime via XML or ODBC
• GST compliance tool or GSTN data for GSTR-2B and e-invoice details
• AP mailbox and supplier portal
• Document management system for the invoice archive

• No auto-posting or payment release; AP approves every document
• Uncertain fields and lines flagged, never silently passed
• Bank detail changes printed on an invoice are flagged, not accepted
• Duplicate checks across suppliers and periods
• Every value linked to its source page and every override logged

• Checks support GST input tax credit conditions by comparing invoice data with GSTR-2B and e-invoice details; ITC decisions stay with your tax team.
• The audit trail helps evidence internal financial controls over purchase-to-pay for statutory audit.

• Manufacturing

  Supplier Quality Certificate Verification

  Check mill test certificates and certificates of conformance against your material specs, tie heat numbers to GRNs, and flag out-of-spec, missing or reused certificates for IQC.

• Retail, D2C & Quick Commerce

  Vendor Invoice and Credit Note Reconciliation

  Match vendor invoices, GRNs, RTVs and credit notes, recalculate what each vendor owes you from the agreements, and chase missing or short credit notes with evidence.

• Accounting, Audit & Consulting

  GST Return Reconciliation (GSTR-2B vs Books)

  Match GSTR-2B and 2A data against the purchase register invoice by invoice, find ITC at risk before GSTR-3B is filed, and draft supplier follow-ups for approval.

• Logistics & Supply Chain

  Freight Invoice Audit Against Rate Contracts

  Audit every carrier or transporter freight bill against your rate contracts, shipment data and PODs, recalculate each charge and flag overbilling, duplicates and unsupported surcharges.