Meera's company hit ₹7.5 cr last FY. On 1 August this year her CA sent her a panic message — "You're now covered by e-invoicing. Every B2B invoice must get an IRN."
She thought she already did e-invoices — she emails them as PDFs! Spoiler: that's not what e-invoicing means.
- Mandatory if aggregate turnover > ₹5 cr (from 1 Aug 2023).
- Every B2B invoice must be reported to the IRP (Invoice Registration Portal) to get an IRN + QR code.
- Applies to B2B, exports, RCM. Not B2C below ₹2.5L, not composition dealers.
- Invoice without a valid IRN (when you're covered) = invalid → buyer can't claim ITC.
What e-invoicing actually is
Before you send the invoice to your buyer, you upload its data to the government's Invoice Registration Portal (IRP). The IRP does four things, in milliseconds:
👉 Validates the data
👉 Issues a unique 64-character Invoice Reference Number (IRN)
👉 Generates a QR code that embeds key invoice data
👉 Auto-pushes the data to GSTN (your GSTR-1) and the NIC e-way bill portal
You then print the invoice with the IRN and QR code on it and send to the buyer. Without these, the invoice is legally invalid.
Are you covered?
The first batch of large enterprises.
Mid-large rolled in.
SMEs got covered.
Most mid-sized businesses. Threshold likely to drop further.
Turnover = aggregate turnover in any preceding FY since 2017-18. Crossed it once? You stay covered.
What's NOT covered (even if you cross the threshold)
- SEZ developers (but SEZ units are covered)
- Insurance, banking, financial institutions, NBFCs
- Goods Transport Agency (GTA)
- Passenger transportation services
- Multiplex / cinema ticket suppliers
- B2C invoices below ₹2.5L (above ₹2.5L need only QR, not IRN)
- Composition dealers
The 6-step flow
einvoice1.gst.gov.in → register your GSTIN. Get API credentials if integrating from ERP.
API integration from your billing system, or a GSP / ASP service (ClearTax, Masters India, IRIS), or bulk upload on the portal (under ~100 invoices/month).
Schema v1.1 — ~140 fields, ~30 mandatory. Your software handles the mapping.
Send JSON to IRP. Get back IRN + QR (instant).
Send to buyer. They scan the QR to verify.
Every e-invoiced invoice flows to your GSTR-1 automatically. Verify before filing — amendments and credit notes sometimes need manual check.
The 3 most-common mistakes
👉 Issuing the invoice before getting IRN. An invoice without IRN (when you're covered) is legally invalid. Buyer can't claim ITC. Always: generate IRN first, then print + dispatch.
👉 Wrong HSN or buyer GSTIN. The IRP rejects. You get an error code. Fix the source data — don't change the invoice number to work around it.
👉 Missing the 24-hour cancellation window. Cancel-and-reissue is only allowed within 24 hours of IRN generation. After that, only credit / debit notes can correct.
E-invoicing isn't extra work once it's set up. Same data flows automatically into GSTR-1, GSTR-2B (your buyer's), and the e-way bill system. No double entry. The pain is the setup; the daily use is a time-saver.
How to pick a method — for your scale
Direct API
High volume
Your ERP / billing software talks to IRP directly. Best for 500+ invoices/month. Initial dev work, then zero touch.
GSP / ASP
Middle ground
ClearTax, Masters India, IRIS, etc. Pre-built connectors to Tally / Zoho / SAP. Sweet spot for 50–500 invoices/month.
Bulk upload
Manual, low volume
Upload Excel / JSON on the IRP portal. Free, manual, fine for < 100 invoices/month.
The pain of e-invoicing is the setup — once a system, never again. Day 1 to day 365, the daily use is one click.
Quick answers
No IRN required for B2C. But if your turnover > ₹500 cr, you must display a dynamic QR code on B2C invoices.
Yes, within 24 hours of IRN generation. After that window, only credit / debit notes can adjust.
You can issue the invoice without IRN temporarily. Once IRP is back, generate IRN within 7 days (system auto-tracks).
No, but the e-invoice IRN can be used to generate an e-way bill directly (data flows automatically). Two separate compliance requirements still.
Any preceding FY since 2017-18. Once you crossed it in any FY, you remain covered going forward — even if turnover drops later.
When you might want help
The hard part is the 2-week setup — picking the right GSP / ASP, mapping your invoice fields to the schema, training the billing team, and handling exceptions (RCM, exports, credit notes). After that it runs itself.
Need e-invoicing setup?
API integration, schema mapping, training, go-live support. Live in 2 weeks.