E-Invoicing & QR Codes: Who Needs Them and How They Work
E-invoicing changed how B2B invoices work for larger businesses: instead of an invoice being valid the moment it's issued, it must first be electronically registered with a government system and stamped with a unique reference number.
Who it applies to
E-invoicing is mandatory for businesses with aggregate turnover above ₹5 crore in any financial year since 2017-18, calculated at the PAN level (all GSTINs under the same PAN combined). This threshold has been progressively lowered by notification several times since e-invoicing was introduced — it started much higher and has stepped down over successive years — so don't assume last year's threshold still applies without checking.
What it applies to
E-invoicing covers B2B invoices, invoices to government entities (B2G), exports, and supplies to SEZ units. It does not apply to B2C retail sales.
How the process works
- The supplier generates the invoice in their own accounting/billing system, in the required JSON format.
- That data is uploaded to the Invoice Registration Portal (IRP).
- The IRP validates it, generates a unique Invoice Reference Number (IRN) and a QR code, and returns both to the supplier.
- The QR code and IRN are printed on the invoice given to the buyer — the QR code itself encodes key details (GSTINs, invoice number and date, value, HSN, IRN) for quick offline verification.
Why the IRN matters so much
An invoice that should have been e-invoiced but wasn't registered on the IRP — i.e., has no valid IRN — is treated as legally invalid under Rule 48(4). Beyond the supplier's own penalty exposure, this leaves the recipient unable to claim Input Tax Credit on that invoice, which is why buyers above the threshold increasingly check for a valid IRN/QR code before accepting an invoice.
How this connects to GSTR-1
E-invoice data auto-populates the corresponding fields in GSTR-1, reducing manual entry — one of the practical benefits for businesses once the system is integrated, beyond just compliance.
Key takeaways
- E-invoicing is mandatory above ₹5 crore turnover (PAN-level), for B2B/B2G/export/SEZ invoices — not B2C.
- An invoice without a valid IRN from the IRP is legally invalid and blocks the buyer's ITC.
- The turnover threshold has been lowered multiple times by notification — always confirm the current figure.
Frequently asked questions
No — they're separate systems for different purposes. E-invoicing authenticates the invoice itself for B2B transactions above a turnover threshold; the E-Way Bill tracks physical movement of goods above a value threshold, and can apply even to businesses not required to e-invoice.
E-invoicing generally becomes mandatory from the start of the financial year following the one in which turnover first crossed the threshold, and continues to apply in subsequent years even if turnover later drops — confirm the exact continuation rule current at the time.