🚨 New 2025 Update: E-Invoice reporting must happen within 30 days for AATO ≥ ₹10 Cr (Effective April 1, 2025). Visit IRP Portal →
Updated March 2026 · GST Compliance Guide

E-Invoicing Under GST — Everything You Need to Know

From turnover thresholds and IRN generation to GST notifications and compliance deadlines — the most complete, current e-invoicing reference for Indian businesses.

₹5 CrMandatory Threshold
30 DaysMax Reporting Window
6+IRP Portals Available
64-CharUnique IRN Hash
Jan 2020System Launched
Check Your Applicability View GST Notifications

What is E-Invoicing?

A structured understanding of India's GST electronic invoicing mandate

E-invoicing under GST — formally termed electronic invoicing — is not a system that generates your invoices for you. It is a reporting mechanism where invoices you already generate through your own accounting or ERP software must be submitted to the Invoice Registration Portal (IRP) for authentication and assignment of a unique identifier.

Once authenticated, the IRP returns a 64-character Invoice Reference Number (IRN), a digitally signed invoice payload, and a QR code. Only invoices bearing a valid IRN are treated as legally compliant under Rule 48(4) of the CGST Rules.

Key Clarification: E-invoicing does not mean logging into the GST portal and typing your invoice there. Your billing software generates the invoice in the standard JSON schema, and the data is pushed to the IRP electronically — automatically.
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Authentication via IRP

Each invoice is validated against GSTN master data. Errors in GSTIN, HSN, or tax amounts are caught at the source — before the invoice reaches the buyer.

Auto-population to GSTR-1

Once IRN is generated, invoice data flows directly into your GSTR-1 return and Part-A of the e-way bill — eliminating duplicate data entry.

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Standard JSON Schema

Invoices must follow a government-prescribed JSON schema (e-invoice standard) with mandatory fields defined by GSTN — ensuring interoperability across platforms.

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Real-time GST Intelligence

The government gains real-time B2B transaction visibility, reducing tax evasion, fake ITC claims, and circular trading. Legitimate taxpayers benefit through streamlined refunds.

How Does E-Invoicing Work?

The complete technical and operational flow from invoice creation to buyer receipt

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1. Generate Invoice

Supplier creates invoice in their ERP/billing software per the e-invoice standard schema

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2. Upload to IRP

Invoice data in JSON format is pushed to the IRP via API, web form, or offline utility

3. IRP Validates

IRP validates GSTIN, invoice schema, deduplication, HSN codes, and tax calculations

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4. IRN Generated

A 64-character unique hash (IRN) is generated and invoice is digitally signed with QR code

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5. Data Shared

Authenticated data flows to GST portal (GSTR-1) and e-way bill system automatically

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6. Issue to Buyer

Supplier sends the digitally signed, IRN-embedded invoice to the buyer — the only valid invoice

⚠ Cancellation Window: An e-invoice can only be cancelled within 24 hours of IRN generation on the IRP portal. After this window, adjustments must be made through a Credit Note.

Threshold & Applicability

Who must generate e-invoices, and under what conditions

AATO Threshold Effective Date Reporting Window Notification Status
₹500 Crore & above October 1, 2020 No limit (then) No. 70/2019 – CT Active
₹100 Crore & above January 1, 2021 30 days (from Nov 2023) No. 88/2020 – CT Active
₹50 Crore & above April 1, 2021 30 days No. 05/2021 – CT Active
₹20 Crore & above April 1, 2022 30 days No. 01/2022 – CT Active
₹10 Crore & above October 1, 2022 30 days (from Apr 2025) No. 17/2022 – CT 30-day rule now applies
₹5 Crore & above August 1, 2023 No fixed limit* No. 10/2023 – CT Current Minimum

* For AATO below ₹10 Cr, there is no statutory 30-day window; however, timely upload is strongly recommended for ITC continuity.

How is AATO calculated? Aggregate Annual Turnover is computed on a PAN-level basis — meaning the combined turnover of all GSTINs registered under a single PAN across India for any financial year from 2017-18 onwards is considered. Crossing the threshold in any preceding year triggers applicability from the start of the next financial year.

Sector-Specific Thresholds

🏭 Manufacturing

Threshold: ₹10 Crore. Covers all B2B sales including goods supplied to distributors, retailers, or businesses. B2C exempt.

🛒 Trading / Wholesale

Threshold: ₹5 Crore for B2B transactions. B2C transactions generally remain outside the mandate.

💼 Services

Threshold: ₹5 Crore for IT, consulting, and export-oriented services. Many other service categories remain exempt.

E-Invoicing: The Complete Timeline

From GST Council approval in 2019 to the current mandate

September 2019

GST Council Approves Standard Format

In its 37th meeting, the GST Council approved the standard format for e-invoicing after extensive consultations with ICAI and industry bodies.

January 2020

System Goes Live (Voluntary Phase)

E-invoicing system launched on a voluntary basis for testing. Mandatory rollout deferred from April 2020 due to COVID-19.

October 2020

Phase 1 — ₹500 Crore Threshold

Mandatory for businesses with AATO ≥ ₹500 Cr. Notification No. 70/2019 – CT operationalized.

January 2021

Phase 2 — ₹100 Crore Threshold

Expanded to businesses with AATO ≥ ₹100 Cr. Notification No. 88/2020 – CT issued.

April 2021 – April 2022

Rapid Expansion — ₹50 Cr then ₹20 Cr

Two successive reductions: ₹50 Cr (Apr 2021) and ₹20 Cr (Apr 2022) brought mid-sized businesses under the mandate.

October 2022

Phase 5 — ₹10 Crore Threshold

Notification No. 17/2022 – CT brought smaller enterprises under the mandate. Approximately 1.3 lakh additional taxpayers covered.

August 2023

Phase 6 — ₹5 Crore (Current Minimum)

Notification No. 10/2023 – CT extended mandate to AATO ≥ ₹5 Cr — the current threshold. Millions of SMEs now covered.

November 2023

30-Day Reporting Rule — ₹100 Cr+

Businesses with AATO ≥ ₹100 Cr mandated to report e-invoices within 30 days of issuance. IRP will reject older invoices.

April 2025

30-Day Rule Extended to ₹10 Crore+

GSTN Advisory No. (November 2024) extended the 30-day reporting window to AATO ≥ ₹10 Cr, effective April 1, 2025. MFA also becomes mandatory for all taxpayers.

February 2026

RSP Validation Relaxation

Notification No. 20/2025 – CT relaxed TotItemVal validations for RSP-based invoices (errors 2194, 2234, 2235 suppressed) with effect from Feb 1, 2026.

Documents Covered Under E-Invoicing

Not every document type requires IRN generation. Know what's in scope.

✅ Covered (IRN Required)

  • Tax Invoice (B2B, B2G, Export)
  • Credit Notes (B2B, B2G, Export)
  • Debit Notes (B2B, B2G, Export)
  • Reverse Charge Invoices (B2B)
  • Invoices for SEZ Developer (not SEZ Unit)
  • Deemed Export Invoices
  • ✕ Not Covered (No IRN Needed)

  • B2C Invoices (end consumers)
  • Import Invoices / Bills of Entry
  • Job Work Delivery Challans
  • ISD Invoices
  • Delivery Challans
  • Bill of Supply (exempt supplies)
  • Who is Exempt from E-Invoicing?

    Certain categories are specifically excluded per Rule 48(4) of the CGST Rules, regardless of turnover.

    Banks & Financial Institutions
    Insurance Companies
    NBFCs (Non-Banking Finance)
    Goods Transport Agencies (GTA)
    SEZ Units (not developers)
    Passenger Transport Services
    Multiplex Cinema Admissions
    Government Departments (UIN)
    Pro Tip (2026): Exempt businesses should register for the "E-Invoice Exemption Declaration" on the GST portal to avoid automated compliance notices from GSTN. This became increasingly important as automated scrutiny of large taxpayers was scaled up in late 2025.

    E-Invoicing Adoption — Data & Trends

    Visual representation of threshold evolution, taxpayer coverage, and compliance growth

    Threshold Reduction Over Time

    AATO limit (in ₹ Crore) mandated across phases

    Estimated Taxpayer Coverage (Cumulative)

    Approximate taxpayers brought under mandate per phase

    Reporting Window Timeline

    Days allowed to report e-invoice to IRP by AATO segment

    Penalty Exposure by Non-Compliance Type

    Relative financial risk per violation category

    Key GST Notifications on E-Invoicing

    Official CBIC notifications governing the e-invoice mandate — with direct links to the GST notification portal

    70/2019 – CT

    First E-Invoicing Notification — ₹500 Crore Threshold

    Mandated the generation of e-invoices for taxpayers with AATO exceeding ₹500 Crore. Effective October 1, 2020. Introduced the IRN-based authentication system for B2B and export transactions under Rule 48(4).

    ↗ View on CBIC Portal ↗ GST.gov.in Reference

    📅 Issued: December 13, 2019

    88/2020 – CT

    Phase 2 Expansion — ₹100 Crore Threshold

    Extended mandatory e-invoicing to taxpayers with AATO ≥ ₹100 Crore. Effective January 1, 2021. Also covered taxpayers whose aggregate turnover in any financial year from 2017-18 exceeded the threshold.

    ↗ View on CBIC Portal

    📅 Issued: November 10, 2020

    01/2022 – CT

    Phase 4 — ₹20 Crore Threshold

    Lowered the mandatory threshold from ₹50 Crore to ₹20 Crore. Effective April 1, 2022. Significantly widened the net of compliance to mid-tier businesses. Amended Rule 48(4) of CGST Rules.

    ↗ View on CBIC Portal ↗ GST Portal Update

    📅 Issued: February 24, 2022

    17/2022 – CT

    Phase 5 — ₹10 Crore Threshold

    Extended mandate to AATO ≥ ₹10 Crore. Effective October 1, 2022. Brought approximately 1.3 lakh additional taxpayers under the e-invoicing system. Smaller enterprises were given 3–4 months of advance notice to prepare ERP systems.

    ↗ View on CBIC Portal

    📅 Issued: August 1, 2022

    10/2023 – CT

    Phase 6 — ₹5 Crore Threshold (Current Minimum)

    The most sweeping expansion — extending the mandate to all registered taxpayers with AATO ≥ ₹5 Crore. Effective August 1, 2023. This notification brought millions of SMEs and micro-enterprises under mandatory electronic invoicing compliance.

    ↗ View on CBIC Portal ↗ Register on IRP

    📅 Issued: May 10, 2023 · Effective August 1, 2023

    GSTN Advisory Nov 2024

    30-Day Reporting Window Extended to ₹10 Crore+ (Effective April 1, 2025)

    GSTN advisory issued November 5, 2024, extending the 30-day IRP reporting restriction from ₹100 Crore+ to all taxpayers with AATO ≥ ₹10 Crore. From April 1, 2025, IRP will reject any e-invoice submission older than 30 days from the invoice date for this segment.

    ↗ IRP Portal Advisory Section ↗ GST Portal

    📅 Advisory: November 5, 2024 · Effective: April 1, 2025

    20/2025 – CT

    RSP-Based Validation Relaxation (Effective Feb 1, 2026)

    Notification No. 20/2025 – Central Tax (December 31, 2025) suppressed specific validation errors (2194 TotItemVal mismatch, 2234 CGST/SGST mismatch, 2235 IGST mismatch) for invoices where RSP-based tax calculation is applicable and at least one HSN is notified for RSP calculation. Applies to invoices dated on or after February 1, 2026.

    ↗ IRIS IRP Portal Changelog

    📅 Issued: December 31, 2025 · Effective: February 1, 2026

    Official Portals for GST Notifications:
    CBIC GST Portal (cbic-gst.gov.in) — All central tax notifications
    GST Council Updates (gst.gov.in) — Official advisories and circulars
    NIC IRP Portal (einvoice1.gst.gov.in) — Primary IRP for e-invoice registration
    IRIS IRP Portal (einvoice6.gst.gov.in) — Private IRP with detailed advisories

    Penalties for Non-Compliance

    The financial and legal consequences of failing to generate valid e-invoices

    ₹10,000

    Per Invoice — Missing IRN

    Under Section 122 of the CGST Act, issuing an invoice without a valid IRN attracts a penalty of ₹10,000 per invoice. The invoice is also treated as invalid under Rule 48(4).

    100% of Tax

    ITC Denial for Recipients

    Recipients who claim Input Tax Credit based on invoices without a valid IRN risk a demand for 100% of the ITC amount plus interest, as such invoices are treated as void under GST law.

    IRP Rejection

    Late Reporting (>30 Days)

    For AATO ≥ ₹10 Cr (from Apr 2025), the IRP will automatically reject e-invoice submissions older than 30 days. This creates a retroactive compliance gap with no cure mechanism.

    Scrutiny

    Automated GST Notices

    GSTN's automated reconciliation system flags mismatches between e-invoice data and GSTR-1. Non-filers receive machine-generated SCNs (Show Cause Notices) that require formal responses.

    ⚠ Critical: An invoice without a valid IRN is not merely penalized — it is treated as no invoice at all under Rule 48(4). This means the entire transaction may be challenged during assessment, affecting both the supplier (output tax liability) and buyer (ITC eligibility).

    2025-26 Compliance Checklist

    Step-by-step actions every notified taxpayer must complete

    Setup & Registration

    • Verify your AATO across all GSTINs under your PAN for any year from 2017-18
    • Register your ERP/billing software with the NIC IRP (einvoice1.gst.gov.in)
    • Enable API access or choose a GSP/ASP for integration
    • Complete MFA (Multi-Factor Authentication) setup on IRP — mandatory from April 2025
    • Validate your GSTIN, buyer GSTIN, and HSN codes in the master data

    Ongoing Compliance

    • Upload each qualifying invoice to IRP and obtain IRN before issuing to buyer
    • For AATO ≥ ₹10 Cr: ensure every invoice is reported within 30 days of invoice date
    • Cancel within 24 hours if needed; use credit notes after that window
    • Verify auto-population of GSTR-1 and reconcile with your books monthly
    • If exempt: file E-Invoice Exemption Declaration on the GST portal
    • Monitor CBIC and GSTN portals for new advisories and validation changes

    Frequently Asked Questions

    Answers to the questions taxpayers and finance teams ask most often

    Yes. The threshold is based on AATO in any financial year from 2017-18 onwards. Once you cross ₹5 Crore in any year, e-invoicing is mandatory from the next financial year onward — even if subsequent years show lower turnover. There is no provision for opting out once the threshold is crossed.
    The IRP provides a web-based form and an offline Excel utility for taxpayers who don't have ERP integration. However, the government has clarified that invoices are always generated by the taxpayer's own system — the GST portal does not create invoices on your behalf. For high-volume businesses, API integration or a GSP (GST Suvidha Provider) is strongly recommended.
    You may cancel the e-invoice on the IRP within 24 hours of IRN generation. After the 24-hour window, the e-invoice cannot be cancelled on the portal — you must issue a Credit Note or Debit Note to adjust the transaction. The original IRN remains permanently on record; it cannot be deleted.
    As per CBIC clarification, a physical invoice is not mandatory if a valid e-invoice (with IRN and QR code) has been issued. The digitally signed invoice returned by the IRP serves as the valid tax invoice. However, many businesses continue to send printed copies for operational clarity, especially in logistics.
    Not always. If all required e-way bill details (transporter ID, vehicle number, etc.) are included in the e-invoice JSON, Part-A of the e-way bill is auto-generated along with the IRN. However, Part-B (vehicle details) must still be updated separately on the e-way bill portal before goods movement. This partial automation significantly reduces duplicate data entry.
    Yes. GSTN has authorized multiple private IRPs (Invoice Registration Portals) in addition to the NIC portal. These include IRIS IRP (einvoice6.gst.gov.in), Cygnet IRP, Clear IRP, and others. All generate the same standard IRN and are equally valid. Businesses may choose based on features, API response times, and pricing.
    The Invoice Reference Number (IRN) is a 64-character alphanumeric hash generated by the IRP using a combination of the supplier's GSTIN, document type, document number, and financial year. It is unique to each invoice and serves as government authentication proof. The invoice number is your own internal sequential numbering — the IRN is the government's reference identifier assigned upon registration.

    Stay Ahead of GST Compliance

    Zerolev helps your business navigate e-invoicing, GSTR filing, and GST audits — with real-time updates whenever CBIC issues new notifications.

    Visit IRP Portal ↗ GST Portal ↗ CBIC Portal ↗