GST invoicing and the four-way document match

The tax invoice and what it must contain

A GST tax invoice issued by a registered supplier is the statutory document that triggers the GST liability for the supplier and the input tax credit for the buyer. The invoice must be issued within the time limits prescribed in the Act, generally before or at the time of despatch in the case of supply of goods, and must contain a defined set of fields. The supplier name, address and GSTIN; the invoice number drawn from a single consecutive series for the financial year; the invoice date; the buyer name, address, and GSTIN where the buyer is registered; the place of supply and the state code; the HSN code at the prescribed level of detail for the supplier turnover band; the description of goods; the quantity and unit; the taxable value; the rate and amount of CGST, SGST or IGST; and the supplier signature or digital signature.

A buyer receiving an invoice that lacks any of these fields cannot claim input tax credit until the supplier issues a corrected invoice. The most common fields missing from sub-standard invoices are the HSN code, the place of supply with the state code, and the supplier signature; each is a basis for ITC denial during a GST audit, with the corresponding interest and penalty exposure for the buyer.

The e-way bill

An e-way bill is required before the movement of goods worth more than fifty thousand rupees, generated on the e-way bill portal at ewaybillgst.gov.in. The bill carries a unique twelve-digit number, the supplier and buyer identifiers, the consignor and consignee, the transport mode and vehicle number, the route distance and the validity period. The validity is one day per two hundred kilometres of route distance for normal cargo and one day per twenty kilometres for over-dimensional cargo, computed from the time of generation. Movement of a consignment without a valid e-way bill, or with a bill whose validity has lapsed, is subject to detention by the GST authorities and a penalty equal to the tax payable, plus the value of the goods in extreme cases.

The e-invoice IRN regime

From 2020 the GST Council has progressively rolled out the e-invoice regime, which requires registered suppliers above a turnover threshold to register every B2B invoice on the Invoice Registration Portal at einvoice1.gst.gov.in before issuing it to the buyer. The registration produces a unique Invoice Reference Number, a digitally signed JSON envelope and a QR code, which must be printed on the invoice. The threshold has stepped down from five hundred crore rupees in turnover at launch to five crore rupees as of August 2023. Sumum Traders LLP issues e-invoices where the regime applies and standard tax invoices where it does not.

The goods receipt note

The goods receipt note is the buyer-side document that records the actual receipt of the consignment at site. It cross-references the purchase order, the delivery challan and the tax invoice, and records the quantity received, any damage observed, any specification deviation and the receiving signatory. The GRN is the foundation of the buyer GST audit because it provides independent evidence that the goods on the invoice were actually received; an invoice with no matching GRN is the first item flagged in any internal audit or external GST inspection.

The four-way document match

The four-way match closes the audit loop on every transaction. The purchase order, the tax invoice, the e-way bill and the goods receipt note must reconcile on supplier identity, buyer identity, item description, quantity, unit rate, taxable value, GST rate and total tax. Any discrepancy between any pair of documents is flagged for resolution before the payment is released. A robust four-way match catches duplicate invoicing, mismatched GST rates, short delivery, over-billing and procurement bypass, and is the single most effective control on a building-material trading business.

Practical implications for buyers

Three practical points follow from the regime above. First, every B2B purchase should be backed by a written purchase order against which the supplier can issue the invoice; verbal orders create gaps in the four-way match that are difficult to close after the fact. Second, the GSTIN on the invoice should match the GSTIN on the buyer registration certificate exactly; even a single character mismatch can deny ITC. Third, the buyer should reconcile the supplier-reported invoice in the GSTR-2A or GSTR-2B return with its own purchase records every month and follow up immediately on any missing entries; ITC for unreported invoices is not claimable indefinitely.

Related reading

The blog article on the procurement checklist walks through the BOQ-to-PO workflow that precedes invoicing. The article on delivery and logistics covers the e-way bill generation and transport documentation. For the order lifecycle as Sumum Traders LLP operates it, see the contact and order lifecycle page.

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