e-Invoicing (electronic invoicing on the IRP — Invoice Registration Portal) has been progressively extended to smaller businesses since 2020. Every threshold reduction brings a new set of clients who need to switch from manual invoicing to IRP-registered B2B invoices. This guide covers the 2026 threshold status, which clients are now covered, the implementation process, and common errors CA firms must help clients avoid.
e-Invoicing Threshold Timeline
| Effective Date | Mandatory for Turnover Above |
|---|---|
| 1 October 2020 | ₹500 crore |
| 1 January 2021 | ₹100 crore |
| 1 April 2021 | ₹50 crore |
| 1 April 2022 | ₹20 crore |
| 1 October 2022 | ₹10 crore |
| 1 August 2023 | ₹5 crore |
| Future (announced/expected) | Check latest GSTN notification for ₹2 crore or lower threshold |
Always verify the current threshold at the GSTN portal (einvoice1.gst.gov.in) or the latest CBIC notification — thresholds change with government notification.
Who Is Currently Exempt from e-Invoicing (2026)
Even above the threshold, these categories are exempt from e-invoicing:
- Banking, financial services, and insurance (BFSI) entities
- Goods transport agencies (GTA)
- Passenger transport services
- Multiplex cinema admission services
- Special Economic Zone (SEZ) units (as the exporter)
- Government departments and local authorities
B2C supplies (to end consumers), SEZ supplies, and export invoices have their own rules — not all require IRP registration even for mandatory entities.
How e-Invoicing Works: The IRP Process
- Invoice is generated in the client's accounting/billing software
- The invoice data is submitted to the Invoice Registration Portal (IRP) in JSON format — either via direct API integration from the accounting software, or via the GST portal's offline utility
- IRP validates the data and generates an IRN (Invoice Reference Number) and a QR code
- The IRN and QR code are embedded into the invoice before it is issued to the buyer
- The invoice data is simultaneously shared with the GST portal — it auto-populates GSTR-1 for the seller
How to Implement e-Invoicing for a Client (CA Firm Checklist)
| Step | Action | Who Does It |
|---|---|---|
| 1 | Confirm applicability — check client's PAN-level aggregate turnover against current threshold | CA firm |
| 2 | Identify client's billing software — check if it supports direct IRP API integration | CA firm + client |
| 3 | If software supports IRP: configure API credentials on the GST portal; test with one sample invoice | CA firm / software vendor |
| 4 | If software does not support IRP: evaluate GST portal offline utility or third-party IRN generation tools | CA firm recommendation |
| 5 | Train client's billing team on the new process (what changes in their workflow) | CA firm |
| 6 | Verify first month's GSTR-1 — confirm e-invoices are auto-populating correctly | CA firm |
Common e-Invoicing Errors and How to Avoid Them
| Error | Consequence | Prevention |
|---|---|---|
| Issuing invoice without IRN | Invoice not considered valid for GST purposes; buyer cannot claim ITC | Block invoice generation in billing software until IRN is received |
| Wrong GSTIN in invoice | IRN rejection; ITC issue for buyer | Validate GSTIN against GST portal before saving the invoice in software |
| Cancelling e-invoice after 24 hours | IRN cannot be cancelled on the IRP after 24 hours; must issue a credit note instead | Train client's billing team: immediate cancellation must happen within 24 hours |
| Not generating IRN for debit notes | Debit notes to B2B buyers also require IRN; missing IRN means the debit note is invalid | Apply the same IRP workflow to debit notes and credit notes |
TaxZeo tracks e-invoicing compliance status for each client and alerts your team when a client crosses the turnover threshold — before the first non-compliant invoice is issued.
Start Free TrialFrequently Asked Questions
If a client's turnover was above the threshold last year but fell below this year, do they still need e-invoicing?
e-Invoicing applicability is based on aggregate turnover in the preceding financial year (PAN-level, all GST registrations combined). If a client's turnover was above the threshold in the preceding year, they remain obligated for e-invoicing in the current year even if their current-year turnover is lower. The exemption from e-invoicing would apply from the following financial year if the current-year turnover falls below the threshold. Track each client's preceding-year turnover at the start of each April to confirm their e-invoicing status for the year.
Does e-invoicing replace the need to file GSTR-1?
No. e-Invoicing and GSTR-1 are separate compliance obligations. e-Invoicing auto-populates data into GSTR-1 in the "System Generated GSTR-1" (auto-drafted), which the taxpayer then reviews and confirms. The taxpayer (or their CA) must still file GSTR-1 by the due date (10th or 11th of the following month). e-Invoicing reduces the manual data entry burden for GSTR-1 but does not eliminate the filing obligation or the review step.