E-invoicing under GST: threshold, IRN and 30-day rule
E-invoicing requires businesses with turnover above ₹5 crore to report B2B invoices to the IRP for an IRN. AATO ₹10 crore+ must report within 30 days.
Short answer
E-invoicing under GST is the system in which businesses above a turnover threshold report their B2B invoices, export invoices and credit and debit notes to a government Invoice Registration Portal (IRP) for a unique Invoice Reference Number (IRN) and QR code. It applies to businesses whose aggregate turnover exceeded ₹5 crore in any financial year from 2017-18.
- Threshold
- Aggregate turnover above ₹5 crore in any year from 2017-18
- Output
- IRN and signed QR code
- 30-day limit
- Applies to AATO of ₹10 crore and above, from 1 April 2025
- Covers
- B2B, exports, credit and debit notes
How e-invoicing works
The business prepares the invoice in its own software in the standard e-invoice schema and uploads it to an IRP. The IRP validates it, generates the IRN and returns a digitally signed invoice with a QR code. Data flows automatically to GSTR-1 and can populate Part A of the e-way bill. An invoice that should have been reported but has no IRN is not treated as a valid tax invoice, which can affect the customer's credit. Since 1 April 2025, taxpayers with aggregate annual turnover of ₹10 crore and above cannot report invoices older than 30 days to the IRP.
Who is exempt
Even above the threshold, certain categories are excluded from e-invoicing. These include SEZ units, insurance companies, banking companies and financial institutions including NBFCs, goods transport agencies, suppliers of passenger transportation services, and suppliers of admission to cinema exhibitions in multiplex screens. Government departments and local authorities are also excluded.
Why it matters for startups
Many startups cross ₹5 crore of aggregate turnover within a few years and must switch on e-invoicing from the following month. Check annual turnover from 2017-18 onwards, because crossing the threshold in any year makes it permanent. Set up IRP integration in your billing software before the threshold is crossed, and report invoices promptly to stay within the 30-day window.
Related services
Sources
- GSTN advisory on 30-day e-invoice reporting limit for AATO of ₹10 crore and above
- e-Invoice Registration Portal (IRP)
- CBIC GST: Acts, rules and notifications
Written by the Refogo Editorial Team from the official sources above and checked on 2026-10-31. Laws, rates and due dates change, and authorities often extend deadlines, so confirm your own case with a qualified professional. This is general information, not legal or tax advice. Read our editorial policy or report an error to support@refogo.com.
Common questions
Is e-invoicing required for B2C invoices?
No. E-invoicing applies to B2B supplies, exports and related credit and debit notes, not ordinary B2C invoices.
What happens if I miss the 30-day reporting window?
If your AATO is ₹10 crore or more, the IRP will not accept the invoice, so it cannot get an IRN. That affects the validity of the invoice and the customer's credit.
Do I stop e-invoicing if turnover falls below ₹5 crore?
No. Once you cross the threshold in any year from 2017-18, the requirement continues.