Since the e-invoicing mandate was extended to businesses with turnover above ₹5 crore in August 2023 (and ₹10 crore from October 2022), the B2B invoice ecosystem has been under significantly tighter GSTN control. The Invoice Registration Portal (IRP) generates an Invoice Reference Number (IRN) for every valid B2B invoice — and from that IRN, GSTN auto-populates the buyer's GSTR-2B. This automation is a compliance win. But it creates a new category of error: the e-invoice data error that silently kills ITC.
Common E-Invoice Errors and ITC Consequences
Wrong Buyer GSTIN
The IRN is generated under a different taxpayer's GSTIN. The correct buyer's GSTR-2B does not show the credit. ITC cannot be availed until amendment is filed by the supplier — which requires IRP cancellation within 24 hours.
HSN Mismatch with Tax Rate
GST rate declared on invoice differs from rate applicable under the declared HSN. IRP generates the IRN (it does not validate rate-HSN consistency) but GSTN's backend flags the mismatch in the buyer's ledger.
IRN Cancellation After 24 Hours
E-invoice cancellation on IRP is only permitted within 24 hours of IRN generation. After that, the supplier must issue a credit note instead — which the buyer must account for correctly to avoid double ITC claim.
Rule 48(4), CGST Rules — E-Invoice Cancellation
The registered person may cancel the invoice reference number, on the Invoice Registration Portal, within 24 hours of the generation of the invoice reference number, if the invoice details are incorrect at the time of generation.
Statutory Reference
A typo in a GSTIN at invoice-generation time is not just a data error — it is a broken ITC link for the buyer that only surfaces 45 days later, when GSTR-2B for the month is generated without the expected credit.
— Sami Tax GST Systems Desk, 2024
E-Invoice Quality Controls for High-Volume Sellers
- Implement a pre-IRN GSTIN validation step in your billing software — the GSTN Taxpayer Search API allows real-time verification of buyer GSTINs before the invoice is generated.
- For amendment errors discovered after 24 hours: issue a Credit Note immediately (not a "cancelled" invoice) and ensure your buyer knows to handle the corresponding GSTR-2B entry.
- For B2B customers who report missing ITC: provide them with both the original IRN number and the credit note reference so they can trace the credit lineage.
- Maintain a monthly e-invoice quality dashboard — track IRN cancellation rates, late-amendment rates, and GSTR-2B mismatch rates as KPIs.
- If your cancellation rate exceeds 1%, there is a systemic billing error worth investigating.