From turnover thresholds and IRN generation to GST notifications and compliance deadlines — the most complete, current e-invoicing reference for Indian businesses.
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.
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.
Standard JSON Schema
Invoices must follow a government-prescribed JSON schema (e-invoice standard) with mandatory fields defined by GSTN — ensuring interoperability across platforms.
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.
The complete technical and operational flow from invoice creation to buyer receipt
1. Generate Invoice
Supplier creates invoice in their ERP/billing software per the e-invoice standard schema
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
4. IRN Generated
A 64-character unique hash (IRN) is generated and invoice is digitally signed with QR code
5. Data Shared
Authenticated data flows to GST portal (GSTR-1) and e-way bill system automatically
6. Issue to Buyer
Supplier sends the digitally signed, IRN-embedded invoice to the buyer — the only valid invoice
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.
🏭 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.
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.
Not every document type requires IRN generation. Know what's in scope.
Certain categories are specifically excluded per Rule 48(4) of the CGST Rules, regardless of turnover.
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
Official CBIC notifications governing the e-invoice mandate — with direct links to the GST notification portal
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
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
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
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
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
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
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
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.
Step-by-step actions every notified taxpayer must complete
Answers to the questions taxpayers and finance teams ask most often
Zerolev helps your business navigate e-invoicing, GSTR filing, and GST audits — with real-time updates whenever CBIC issues new notifications.