GST Compliance · April 2026 Update
Turnover Above ₹5 Crore? Your Step-by-Step Guide to Mandatory E-Invoicing
The 30-Day IRN Rule, common pitfalls, and everything your MSME needs to comply.
As of April 1, 2026, e-invoicing is compulsory for every GST-registered business with an Aggregate Annual Turnover (AATO) exceeding ₹5 Crore. If your turnover crossed this threshold in any financial year from FY 2017–18 onwards, you are covered — effective immediately.
Every few months, the government lowers the e-invoicing threshold and a fresh wave of MSMEs finds itself legally required to do something it has never done before. This time, the net has widened dramatically. Hundreds of thousands of small manufacturers, traders, and service providers who were quietly watching from the sidelines are now in the mandatory e-invoicing bracket.
Over the past few weeks, my inbox has been flooded with panicked messages: “We have no idea where to start,” “Our software doesn’t support it,” “Will we lose ITC if we don’t comply?” This guide is my attempt to answer all of those questions in one place, clearly and practically.
01 — What Is E-Invoicing, Really?
E-invoicing under GST does not mean simply generating a PDF and emailing it to your customer. That is a common and costly misconception.
Under the GST e-invoicing framework, every B2B invoice you generate must first be reported to the Invoice Registration Portal (IRP) — a government system. The IRP validates the invoice data, stamps it with a unique Invoice Reference Number (IRN) and a QR code, and returns it to you. Only then is your invoice legally valid under GST law.
Think of the IRP as a notary for your B2B invoices. Without its stamp, the invoice does not legally exist in the GST ecosystem — and your buyer cannot claim Input Tax Credit (ITC) on it.
What an IRN Looks Like
| Field | Detail |
|---|---|
| Sample IRN | a3c7f9e2b1d8f45a9c3e7b1d4f8a2e6c9b3d7f1a4e8c2b6f9d3a7e1c5b4f8a2 |
| What it is | A 64-character alphanumeric hash generated by the IRP. Unique to each invoice, computed from your GSTIN, invoice number, financial year, and document type. You cannot create it yourself — only the IRP can issue it. |
| Must appear on | Every copy of the invoice sent to your buyer, transporter, and retained in your records. The QR code encodes the IRN and key invoice details for easy verification. |
| Auto-populates | GSTR-1 — from April 2026, the IRP pushes data directly to the GST portal, reducing manual reconciliation significantly. |
02 — Who Is Covered Under the ₹5 Crore Threshold?
Applicability is based on your Aggregate Annual Turnover (AATO) — the total taxable turnover across all your GSTINs, across all states, for the same PAN. If this figure exceeded ₹5 Crore in any financial year from FY 2017–18 onwards, you are mandatorily covered from April 1, 2026.
| Status | Document / Supply Type | Notes |
|---|---|---|
| Included | B2B Invoices | All invoices to GST-registered recipients, regardless of value. |
| Included | Debit & Credit Notes | Pertaining to B2B supplies also require IRN generation. |
| Included | Export Invoices | Including SEZ supplies with payment of tax. |
| Excluded | B2C Invoices | Invoices to unregistered consumers do not require IRN. |
| Excluded | Nil-Rated / Exempt Supplies | Outside the ambit of e-invoicing entirely. |
| Excluded | Certain Sectors | Banks, NBFCs, insurers, GTA, passenger transport, SEZ units (as supplier) remain exempt. |
To check your AATO: GST Portal → Services → User Services → View My Profile. Your AATO is displayed on the dashboard.
03 — The 30-Day IRN Rule: The Most Misunderstood Provision
Starting from August 1, 2023, a time-limit was imposed on IRN generation. For businesses with AATO above ₹100 Crore, the window is currently 30 days from the invoice date. The GSTN has indicated this same rule will apply to the newly onboarded ₹5–100 Crore bracket.
In plain terms: you cannot upload an invoice to the IRP more than 30 days after the invoice date.
30-Day Rule: Date Examples
| Invoice Date | Latest IRN Date | Uploaded On | Result |
|---|---|---|---|
| April 1, 2026 | April 30, 2026 | April 28 | Valid |
| April 1, 2026 | April 30, 2026 | May 2 | Permanently Rejected |
| May 15, 2026 | June 14, 2026 | June 10 | Valid |
| May 15, 2026 | June 14, 2026 | June 15 | Permanently Rejected |
Businesses that batch invoices weekly or monthly will hit this wall hard. An invoice dated the 1st uploaded on the 2nd of the next month — even by one day — will be permanently rejected by the IRP. No appeal, no exception, no grace period.
The IRN Lifecycle — Step by Step
| Step | Action |
|---|---|
| Step 1 | Prepare the invoice in your accounting or ERP system. |
| Step 2 | Your software pushes the invoice JSON to the IRP via API in real time. |
| Step 3 | The IRP validates the data and returns an IRN + QR code (typically under 2 seconds). |
| Step 4 | The signed e-invoice is issued to your buyer with the QR code embedded. |
| Step 5 | The IRP automatically pushes data to your GSTR-1 — no manual entry needed. |
04 — 7-Day Onboarding Plan: Get Compliant Fast
If you have not yet begun, here is the fastest path to compliance. Seven days is achievable if you move decisively.
Day 1
Visit einvoice1.gst.gov.in. Log in with your GST credentials and enable e-invoicing for your GSTIN. This is the foundational step — everything else depends on it.
Day 2
Check whether your current billing or ERP software is IRP-integrated. Ask your vendor directly. Most MSME tools (Tally, Zoho, Busy) now support e-invoicing natively.
Day 3
On the IRP portal, generate your Client ID and Client Secret, or choose a GSP (GST Suvidha Provider) as your middleware.
Day 4–5
The GSTN provides a sandbox environment. Generate test IRNs before going live. Identify and fix any data format issues in your invoice master.
Day 6
Your invoice must include the IRN, QR code, IRP acknowledgement number, and date. Update your stationery and software templates accordingly.
Day 7
Start generating real IRNs for all new B2B invoices. Inform your billing team and buyers. Monitor the first live batch closely.
Generate IRNs manually through einvoice1.gst.gov.in using the web interface or Excel bulk upload (up to 1,000 invoices at a time). Free and fully compliant for smaller volumes.
05 — Penalties for Non-Compliance
Non-compliance with e-invoicing provisions under the CGST Act is taken seriously. The table below summarises the key penalties applicable to you and your buyers.
| Violation | Applicable Penalty |
|---|---|
| Issuing a B2B invoice without a valid IRN | ₹10,000 per invoice (Section 122, CGST Act) |
| Buyer claiming ITC on invoice without IRN | ITC reversal + 18% interest + penalty equal to ITC amount |
| IRN not generated within 30 days of invoice date | Invoice permanently invalid; buyer loses ITC entitlement |
| Transporting goods without e-way bill linked to IRN | Vehicle & goods detained; penalty up to 200% of tax (Section 129) |
| Repeated or wilful non-compliance | Prosecution under Section 132; possible GST registration suspension |
If your supplier issues you an invoice without a valid IRN and you claim ITC on it, you are equally at risk. Always verify the IRN and QR code on invoices you receive. The GSTN provides a free QR code verification app for this purpose.
06 — Cancellation of an E-Invoice
An IRN can be cancelled only within 24 hours of its generation. After that window closes, the correct approach is to issue a credit note against the original invoice — not to cancel and reissue.
| Rule | Detail |
|---|---|
| Cancellation window | Within 24 hours of IRN generation only. |
| After 24 hours | Issue a credit note against the original invoice. IRP cancellation no longer possible. |
| Cancelled IRN re-use | Not allowed. Create a new invoice number and a fresh IRN. |
| If e-way bill is linked | Cancel the e-way bill first, then cancel the IRN. They are linked and must be cancelled in sequence. |
| Reason required | Yes — select from: Duplicate, Data Entry Error, Order Cancelled, or Others. |
07 — Frequently Asked Questions
Your obligation is triggered by your AATO, not the nature of your supplies. However, e-invoicing applies only to your B2B invoices, export invoices, and SEZ supplies. Your B2C invoices do not need an IRN.
No. Composition scheme taxpayers are expressly exempt from e-invoicing, regardless of turnover.
Use the GSTN free web portal or Excel bulk upload as an interim measure. Low-cost IRP-integrated options for MSMEs include Tally with e-invoicing add-on, Zoho Books, ClearTax e-Invoice, and Masters India — most under ₹10,000/year.
Yes. Once your IRN is generated, the IRP pushes invoice data directly to the GST portal’s auto-populated GSTR-1 section. You still need to review before filing, but manual data entry is largely eliminated.
If within the 30-day window, generate the IRN immediately. If the window has passed, those invoices are permanently invalid for ITC. Issue credit notes against them and reissue fresh invoices with new IRNs.
Yes, for consignments exceeding ₹50,000 involving movement of goods. However, when generating an IRN, you can simultaneously generate the e-way bill by including transport details in the same JSON payload — saving an extra step.
08 — Compliance Checklist for MSMEs
- ✓ Verified AATO on GST portal and confirmed obligation to comply from April 2026.
- ✓ Registered as an e-invoicing taxpayer on einvoice1.gst.gov.in (or through a GSP).
- ✓ Obtained API credentials or subscribed to an IRP-integrated software / GSP service.
- ✓ Tested IRN generation successfully in the GSTN sandbox environment.
- ✓ Updated invoice template to include IRN, QR code, and IRP acknowledgement number and date.
- ✓ Trained billing staff on the new workflow and the 30-day rule.
- ✓ Set up an internal SOP: generate IRN at time of invoice creation, not at month-end.
- ✓ Configured GSTR-1 reconciliation to verify auto-populated e-invoice data before filing.
- ✓ Communicated the change to key buyers and suppliers so they expect QR-coded invoices.
- ✓ Reviewed all invoices from April 2026 onwards for missing IRNs and remediated promptly.
Final Words:
E-invoicing is not the compliance monster it appears to be once you are set up. The businesses already in the ₹10 Crore and ₹20 Crore brackets find that GSTR-1 auto-population and elimination of manual data entry saves them time every month.
The transition period is uncomfortable, but the steady state is genuinely more efficient. Do not delay. The penalties are real, the ITC risk to your buyers is real, and the 30-day window does not care about your software’s update schedule.
Consult a professional with GST expertise before you incur penalties, not after.
Disclaimer: This article is for educational and informational purposes only and does not constitute formal legal or tax advice. GST law is subject to frequent amendments — always verify current provisions with a qualified professional or the official GSTN portal before acting.
