GST E-Invoice October 2026: ₹5 Crore Rule & 30-Day IRN Limit

What Happened?

The Central Board of Indirect Taxes and Customs (CBIC) has announced expanded GST e-invoicing mandatory coverage effective October 2026. Businesses with annual turnover of ₹5 crore and above must now generate Invoice Reference Numbers (IRNs) for all business-to-business (B2B) invoices. Additionally, a critical compliance rule requires all invoices with transaction value exceeding ₹10 crore to be reported to the IRP (Invoice Registration Portal) within 30 days. This marks a significant shift in India's digital tax compliance infrastructure.

Background & Legal Context

GST e-invoicing under the Goods and Services Tax Act, 2017

GST e-invoicing is governed under Section 16 of the GST (Supp. Supplies) Rules, 2017 and recently aligned with provisions in the Income Tax Act 2025 for digital compliance and record-keeping. The e-invoice system ensures real-time reporting of B2B transactions to tax authorities.

• First Phase (April 2020): E-invoicing was mandatory for businesses with turnover above ₹500 crore.
• Second Phase (October 2021): Threshold reduced to ₹100 crore.
• Third Phase (April 2022): Further reduced to ₹50 crore.
• Current Phase (October 2026): Expanded to ₹5 crore and above, with enhanced 30-day reporting for high-value invoices.

Why This Rule? The expansion aims to increase tax transparency, reduce GST evasion, and capture real-time transaction data across India's supply chain. The ₹10 crore 30-day reporting rule ensures government oversight of high-value B2B transactions that carry higher revenue risk.

What Does This Mean for You?

1. Who Must Comply?

• All registered GST dealers with annual turnover ≥ ₹5 crore (for FY 2025-26 or FY 2026-27).
• Both suppliers and recipients must have valid GSTIN.
• Applies to all B2B invoices issued for taxable supplies of goods and services.
• Exemption: Invoices below ₹5,000 may be exempt (clarification awaited).
• Exclusions: B2C (business-to-consumer) invoices, supply to unregistered persons, and export invoices do NOT require IRN generation, though they must still be recorded in GST returns.

2. The 30-Day IRN Reporting Rule (Critical Compliance Point)

Any B2B invoice with transaction value exceeding ₹10 crore must be reported to the IRP within 30 calendar days from the invoice date. Failure to report within this period attracts:

• Penalties under GST law (penalty amount to be notified).
• Risk of GST demand notice with interest.
• Possible denial of Input Tax Credit (ITC) for the recipient.
• Reputational impact in GST compliance profile.

Example: A manufacturer in Jaipur issues an invoice of ₹12 crore to a retailer on 5 October 2026. The IRN must be generated and reported to IRP by 4 November 2026. Reporting on 5 November would be late compliance.

3. Impact on GST Returns (GSTR-1)

E-invoice data (IRN) will be auto-populated into GST returns (GSTR-1). Manual discrepancies between e-invoice data and GSTR-1 will trigger GST audit flags and possible notices under Section 64 of the GST Act.

4. ITC Implications

Buyers cannot claim Input Tax Credit (ITC) if:

• The supplier's invoice lacks a valid IRN.
• The invoice was not reported to IRP within 30 days (for ≥₹10 crore invoices).
• GSTR-1 and e-invoice details do not match.

This creates a cascading impact on cash flow and working capital for the buyer.

5. Technology & System Readiness

Businesses must ensure:

• Billing software is IRP-certified and updated for October 2026 rules.
• Staff is trained on IRN generation and 30-day reporting deadlines.
• Integration with GST portal is tested before month-end invoicing.
• Backup systems exist for IRP portal downtime.

What Should You Do Now?

Immediate Action Items (October 2026)

• Audit Your Turnover: Check FY 2025-26 revenue in audited financials or GST annual returns. If ≥₹5 crore, you MUST comply from October 2026.
• Software Upgrade: Contact your billing/ERP vendor immediately. Ensure your system is certified by GST portal for October 2026 e-invoicing rules. Do NOT delay this—system failures will not be accepted as excuse for late reporting.
• Create a 30-Day Tracker: Maintain a log of all invoices ≥₹10 crore. Flag them for 30-day reporting deadline. Use calendar reminders or automate via software.
• Train Your Team: Finance, accounts, and billing teams must understand IRN generation, 30-day rule, and ITC consequences. Conduct internal workshop before month-end.
• Update Vendor Terms: If you buy from suppliers ≥₹5 crore turnover, inform them you expect IRN-enabled invoices. Clarify responsibility for late reporting issues.
• Reconcile GST Data: Before filing GSTR-1, reconcile e-invoice data with your billing records to avoid GSTR-1/e-invoice mismatch.
• Insurance & Compliance: Consider purchasing GST compliance audit insurance if you deal in high-value B2B transactions.

For Large Groups (Turnover > ₹50 Crore)

• Appoint a dedicated GST e-invoice compliance officer.
• Implement automated 30-day reporting workflow to eliminate manual errors.
• Conduct quarterly internal compliance audits.
• Maintain documentary evidence of IRN generation and reporting for each high-value invoice.

Key Takeaways

• October 2026 E-Invoice Threshold: GST e-invoicing now mandatory for all B2B invoices issued by businesses with ≥₹5 crore annual turnover. No exemptions for certain sectors.
• 30-Day IRN Reporting Rule: Invoices exceeding ₹10 crore must be reported to IRP within 30 days. Late reporting attracts penalties and ITC denial to the buyer.
• ITC at Risk: Buyers cannot claim ITC if supplier's invoice lacks valid IRN or was not reported on time. This impacts working capital and tax liabilities significantly.
• GSTR-1 Mismatch Risk: E-invoice data must match GSTR-1 filing. Discrepancies will trigger GST notices and audit flags under GST Act Section 64.
• Tech-Driven Compliance: Business success depends on certified software, staff training, and automated 30-day tracking. Ignorance or system failures will not be accepted by tax authorities.

Final Word: The October 2026 e-invoice expansion represents the government's push toward a 'no-cash, all-digital' GST regime. Non-compliance is no longer an option—it is financially and reputationally damaging. Act now, automate faster.

Need expert help with this? EaseValue CAs in Jaipur — WhatsApp 63677 44602