Updated March 2026

E-Invoicing Under GST 2026: Who Needs It, How It Works, and How to Comply

E-invoicing is mandatory for businesses with turnover above Rs 5 crore. Every B2B invoice must be registered on the IRP portal. Here is the complete guide to e-invoice rules, process, and compliance.

Vaishali Singh·

What is E-Invoicing Under GST?

E-invoicing (electronic invoicing) under GST is not about creating invoices online — that is what any billing software does. E-invoicing is specifically about registering your B2B invoices with the government's Invoice Registration Portal (IRP) and obtaining an Invoice Reference Number (IRN) and QR code for each invoice. This ensures the government has real-time visibility into B2B transactions across India.

The system was introduced in phases starting October 2020 for businesses with turnover above Rs 500 crore. The threshold has been progressively lowered, and as of 2026, e-invoicing is mandatory for all businesses with aggregate turnover exceeding Rs 5 crore in any financial year since FY 2017-18.

If your business crosses the Rs 5 crore threshold, every B2B invoice, credit note, and debit note must go through the IRP before being shared with the customer. An invoice without a valid IRN is not a legal document — the customer cannot claim input tax credit on it, and it is not reported in your GSTR-1.

myBillPlease currently generates fully GST-compliant invoices with all mandatory fields, HSN codes, and correct CGST/SGST/IGST splits. E-invoicing with IRP integration is on our development roadmap. Businesses below Rs 5 crore do not need e-invoicing — our invoices are fully compliant for you. Use our GST calculator to verify tax amounts.

Who Must Generate E-Invoices?

Threshold and applicability as of March 2026

FeatureMust Generate E-InvoiceE-Invoice NOT Required
Turnover threshold
Above Rs 5 crore (in any FY since 2017-18)
Below Rs 5 crore
B2B invoices
Mandatory — every invoice needs IRN
Not required — regular tax invoice is sufficient
B2C invoices
NOT required — regular invoice is fine
NOT required
Credit notes
Mandatory for B2B credit notes
Not required
Debit notes
Mandatory for B2B debit notes
Not required
Exports
Mandatory for export invoices
Not required
SEZ supplies
Mandatory
Not required
Composition dealers
Not applicable (no tax invoices)
Not applicable
Insurance/banking
Exempt (as of 2026)
Exempt

How E-Invoicing Works: The Technical Process

Step 1: Generate invoice in your billing software. Create a B2B invoice with all mandatory fields — supplier GSTIN, buyer GSTIN, invoice number, HSN codes, tax amounts, etc. The invoice data must be in the prescribed JSON format (Schema version 1.01).

Step 2: Push to IRP. Your billing software sends the invoice data to the Invoice Registration Portal (IRP) via API. There are multiple IRP portals — the primary one is einvoice1.gst.gov.in. The IRP validates the data — checks for duplicate invoice numbers, validates GSTINs, verifies HSN codes, and ensures mandatory fields are present.

Step 3: IRP generates IRN + QR Code. If validation passes, the IRP generates a unique 64-character Invoice Reference Number (IRN) and a QR code. The QR code contains key invoice details like seller GSTIN, buyer GSTIN, invoice number, date, total value, HSN codes, and the IRN itself.

Step 4: IRP pushes to GST portal. The IRP automatically sends the invoice data to the GST portal, where it auto-populates your GSTR-1 and the buyer's GSTR-2B. This means you don't need to separately upload invoice data when filing GSTR-1.

Step 5: Print/share the invoice with IRN + QR. The final invoice PDF must include the IRN and QR code. Share it with the customer. They can verify the invoice authenticity by scanning the QR code against the GST portal.

Benefits of E-Invoicing

Why the government mandated it and how it helps your business

Auto-Populated GSTR-1

E-invoices auto-populate your GSTR-1 on the GST portal. No manual entry needed for B2B invoices. Just verify and file. This saves hours of data compilation every month.

Faster ITC for Buyers

Your customer sees the invoice in their GSTR-2B almost immediately after IRP registration. They can claim ITC faster because the data is already verified by the government.

Reduced Fraud

Each invoice has a unique IRN verified by the government. Fake invoices used for bogus ITC claims are detectable because they won't have valid IRNs. This protects honest businesses.

E-Way Bill Integration

E-invoices can automatically generate Part A of the e-way bill if the invoice value exceeds Rs 50,000. You just need to add Part B (transport details) on the e-way bill portal.

Interoperability

The standard JSON format means any compliant software can generate e-invoices. You are not locked into one billing platform. Data flows seamlessly between buyer and seller systems.

Audit Trail

Every B2B invoice is registered with the government in real-time. This creates a complete audit trail that simplifies GST audits and reduces the risk of discrepancies during assessment.

Penalties for Non-Compliance with E-Invoicing

Failing to generate e-invoices when required has serious consequences:

Invoice treated as invalid: A B2B invoice without a valid IRN is not a legally valid tax invoice. This means the buyer cannot claim input tax credit on the purchase. If the buyer discovers the missing IRN during GSTR-2B reconciliation, they will refuse to pay or demand a proper e-invoice.

Penalty under Section 122: Issuing an incorrect or incomplete invoice attracts a penalty of Rs 10,000 or the tax amount on the invoice — whichever is higher. For high-value B2B invoices, this can be substantial.

GSTR-1 auto-population fails: Without e-invoicing, your B2B invoices don't auto-populate in GSTR-1. You must enter them manually, increasing the risk of errors and mismatch with the buyer's GSTR-2B.

Business reputation impact: Regular B2B customers who need ITC will stop buying from suppliers who don't generate proper e-invoices. Non-compliance directly affects your sales.

If your turnover is approaching Rs 5 crore, plan for e-invoicing compliance in advance. Ensure your billing software supports IRP integration or have a process for manually generating e-invoices on the portal.

Below Rs 5 Crore? E-Invoicing is Not Required

If your aggregate turnover has never exceeded Rs 5 crore in any financial year since FY 2017-18, e-invoicing does not apply to you. Your regular tax invoices generated through billing software like myBillPlease are fully valid and legally compliant.

For businesses below the threshold, focus on getting the basics right: all 16 mandatory invoice fields, correct HSN codes, proper CGST/SGST/IGST split, and timely GSTR-1 and GSTR-3B filing. myBillPlease handles all of this with automatic calculations, 7 PDF templates, and auto-generated GST reports.

When the government further lowers the e-invoicing threshold (which is expected in future years), myBillPlease will add IRP integration as an automatic update. You won't need to switch software or migrate data.

IRP Portal Details and API Access

The Invoice Registration Portal is managed by the National Informatics Centre (NIC). There are multiple IRP portals for load distribution:

Primary IRP: einvoice1.gst.gov.in — the main portal for registration, sandbox testing, and production API access.

How to register for API access: If your billing software doesn't have built-in e-invoicing, you can generate e-invoices directly on the IRP portal. Log in with your GST credentials, enter invoice details in the web form, and generate the IRN. For bulk invoices, use the Excel bulk upload feature.

For software developers: The IRP provides REST APIs for automated e-invoice generation. The API requires client ID and secret obtained through the portal. The sandbox environment at einvoice1.gst.gov.in/Others/SandBoxAPI lets you test before going live.

IRN cancellation: An IRN can be cancelled within 24 hours of generation if the invoice was generated in error. After 24 hours, you must issue a credit note instead. The 24-hour window is strict — there is no extension. Learn more about credit notes and debit notes for corrections after 24 hours. Also check our retail billing guide for industry-specific e-invoicing advice.

Frequently Asked Questions

Below Rs 5 Crore? You're Covered — Start Free

myBillPlease creates fully GST-compliant invoices without e-invoicing complexity. Free plan with unlimited invoices.

Get Started Free
E-Invoicing Under GST: ₹5 Crore Limit & How to Generate 2026 | myBillPlease