What is the e-invoice turnover limit for 2026?

As of 2026, e-invoicing is mandatory for all GST-registered businesses with aggregate annual turnover exceeding INR 5 crore. The government has been progressively lowering this threshold and is expected to eventually make e-invoicing mandatory for all GST-registered businesses regardless of turnover.

Is e-invoice mandatory for manufacturers?

Yes, e-invoice is mandatory for manufacturers whose aggregate annual turnover in any financial year from 2017-18 onwards exceeds INR 5 crore. This applies to B2B supplies (sales to other businesses), exports, and supplies to SEZ. B2C (direct consumer) sales are currently exempt from e-invoicing.

What happens if I do not generate an e-invoice?

If e-invoicing is applicable to you and you issue an invoice without generating an IRN (Invoice Reference Number) from the IRP portal, the invoice is considered invalid under GST law. The recipient cannot claim input tax credit (ITC) on such invoices. You may also face penalties under Section 122 of the CGST Act, which can be up to INR 10,000 per invoice or the tax amount, whichever is higher.

Can I cancel or amend an e-invoice?

You can cancel an e-invoice on the IRP portal within 24 hours of generation. After 24 hours, cancellation on the IRP is not possible. You must issue a credit note or debit note (which also needs to be reported on the IRP) to adjust the original invoice. Amendment of e-invoices is not allowed; you must cancel and reissue.

How does ERP software help with e-invoice compliance?

ERP software automates e-invoice generation by integrating directly with the IRP portal via API. When you create a sales invoice in the ERP, it automatically generates the JSON payload, submits it to the IRP, receives the IRN and QR code, and embeds them in the invoice PDF. This eliminates manual data entry on the portal, reduces errors, and ensures every applicable invoice gets an IRN without manual intervention.

GST e-Invoice for Manufacturers: Complete Guide 2026

GST e-invoicing has moved from being a requirement for large enterprises to something that affects most manufacturers in India. If your factory's aggregate turnover exceeds INR 5 crore in any financial year since 2017-18, you are required to generate e-invoices for all B2B supplies. Non-compliance can result in penalties, ITC denial for your customers, and disruption to your supply chain.

This guide covers everything a manufacturer needs to know about GST e-invoicing in 2026: who needs to comply, how the system works, the step-by-step process for generating e-invoices, common errors and how to fix them, and how ERP software eliminates the manual burden.

TL;DR: e-Invoice is mandatory for manufacturers with turnover above INR 5 crore. Every B2B invoice must be reported to the IRP (Invoice Registration Portal) to get a unique IRN and QR code. Invoices without IRN are invalid and the buyer cannot claim ITC. ERP software automates the entire process via API integration with the IRP, eliminating manual portal visits.

What Is GST e-Invoice?

GST e-invoice is not an invoice generated electronically (that would be any computer-generated invoice). It is a system where your invoice details are reported to a government portal called the Invoice Registration Portal (IRP), which validates the data, assigns a unique Invoice Reference Number (IRN), digitally signs the invoice, and generates a QR code. This IRN and QR code must appear on the invoice you give to your customer.

The purpose of e-invoicing is to create a standardised, machine-readable invoice format across all businesses in India. This enables automatic population of GST returns (GSTR-1), eliminates the need for manual data entry, and reduces tax evasion by creating a real-time audit trail of all B2B transactions.

Key Terminology

IRP (Invoice Registration Portal): The government portal (einvoice1.gst.gov.in) where invoice data is submitted and IRNs are generated. NIC (National Informatics Centre) operates the main IRP.
IRN (Invoice Reference Number): A unique 64-character hash generated by the IRP for each invoice. This is the unique identifier for the e-invoice in the GST system.
QR Code: A machine-readable code containing key invoice details (supplier GSTIN, buyer GSTIN, invoice number, date, value, IRN). Must be printed on the invoice.
JSON Schema: The standardised data format in which invoice details must be submitted to the IRP. The schema includes fields for supplier details, buyer details, item details, HSN codes, tax amounts, and more.

Who Needs to Generate e-Invoices?

As of 2026, e-invoicing is mandatory for all GST-registered businesses with aggregate annual turnover exceeding INR 5 crore in any financial year from 2017-18 onwards. For manufacturers, this covers:

All B2B sales invoices — invoices issued to other GST-registered businesses
Export invoices — supplies made to businesses outside India
Supplies to SEZ — invoices for Special Economic Zone units or developers
Credit notes and debit notes — these also need to be reported to the IRP

What Is Exempt from e-Invoicing?

B2C (business-to-consumer) sales where the buyer is not GST-registered
Job work challans (these are delivery challans, not tax invoices)
Bill of supply for exempt goods
Imports (these are handled through the customs system, not e-invoice)

Important: Even if your current turnover is below INR 5 crore, check if it exceeded this threshold in any previous year starting from 2017-18. The threshold is based on aggregate turnover (all GSTINs combined), not per-unit or per-state turnover.

How the e-Invoice Process Works

The e-invoice generation process follows these steps:

Step 1: Create Invoice in Your Billing System

Generate the sales invoice in your ERP or billing software as usual — with all required fields including supplier GSTIN, buyer GSTIN, HSN codes, quantities, rates, tax amounts, and invoice number.

Step 2: Generate JSON and Submit to IRP

The invoice data is converted into the e-invoice JSON schema format and submitted to the IRP via API or through the web portal. The JSON includes mandatory fields like document type, supply type, item details with HSN codes, and tax breakup.

Step 3: IRP Validates and Returns IRN

The IRP validates the data (checks GSTIN validity, duplicate invoice numbers, schema compliance), generates a unique 64-character IRN, digitally signs the invoice data, generates a QR code, and sends these back to your system.

Step 4: Print Invoice with IRN and QR Code

The IRN and QR code received from the IRP are embedded into your invoice. The printed or PDF invoice must display both the IRN number and the QR code for it to be valid.

Step 5: Auto-Population of GSTR-1

Once the IRN is generated, the invoice data is automatically populated in your GSTR-1 return. You do not need to separately upload these invoices during GSTR-1 filing — they appear automatically in the relevant tables.

Common e-Invoice Errors and How to Fix Them

Manufacturers frequently encounter these errors when generating e-invoices. Here are the most common ones and their solutions:

Duplicate IRN (Error Code 2150): An e-invoice with the same invoice number, financial year, and supplier GSTIN already exists. Check if the invoice was already reported. If you need to reissue, use a different invoice number or cancel the existing IRN first.
Invalid GSTIN of buyer (Error Code 2163): The buyer's GSTIN is either incorrect, cancelled, or suspended. Verify the buyer's GSTIN on the GST portal before issuing the invoice. Maintain updated customer masters in your ERP.
HSN code mismatch (Error Code 2139): The HSN code provided does not exist in the master list or the number of digits is incorrect. For turnover above INR 5 crore, 6-digit HSN codes are mandatory. Verify your HSN code library in your system.
Tax rate mismatch: The tax rate does not match the rate applicable for the HSN code. Ensure your product-tax mapping is correct and up to date with the latest GST rate notifications.
Document date older than allowed: The IRP does not accept invoices dated more than a specified number of days in the past. Generate IRNs promptly after invoice creation — do not accumulate invoices and report them in bulk at month-end.
Schema validation failures: Missing mandatory fields, incorrect data types, or formatting issues in the JSON payload. This is where ERP integration helps — the system ensures all mandatory fields are populated correctly before submission.

How ERP Automates e-Invoice Compliance

Generating e-invoices manually through the IRP web portal is feasible for 5-10 invoices per day. But a manufacturing factory issuing 30-100+ invoices daily cannot afford the manual effort, error risk, and time delay of portal-based generation. This is where ERP-based e-invoice automation becomes essential.

What ERPDrive Automates

One-click IRN generation: When you create a sales invoice in ERPDrive, a single click submits the data to the IRP and retrieves the IRN and QR code. No manual JSON creation, no portal login, no copy-pasting.
Automatic validation before submission: The system validates all mandatory fields (GSTIN format, HSN code validity, tax rate correctness) before sending to the IRP, catching errors before they cause rejections.
Bulk e-invoice generation: Process multiple invoices for IRN generation in a single batch — especially useful at month-end or during high-volume dispatch days.
QR code and IRN on printed invoices: The IRN and QR code are automatically embedded in the invoice PDF template, ensuring every printed invoice is compliant.
e-Way bill integration: For goods valued above INR 50,000, the e-way bill can be generated simultaneously with the e-invoice, using the same data without re-entry.
GSTR-1 reconciliation: Since e-invoiced data auto-populates GSTR-1, the ERP helps you reconcile the auto-populated data with your books and identify any discrepancies before filing.
Credit note and debit note handling: Credit notes and debit notes linked to e-invoiced invoices are also reported to the IRP with proper reference to the original IRN.

Automate Your e-Invoice Compliance

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Best Practices for Manufacturers

Generate IRN immediately after invoice creation. Do not accumulate invoices and generate IRNs in bulk at month-end. The IRP has date restrictions, and delays can cause rejections.
Maintain clean customer masters. Ensure every customer's GSTIN, legal name, and address are accurate and up to date. A single wrong character in a GSTIN causes rejection.
Use correct HSN codes at 6-digit level. Map every product to its correct 6-digit (or 8-digit) HSN code. Incorrect HSN codes can lead to ITC issues for your buyer and notices from the department.
Cancel within 24 hours if needed. If an invoice needs correction, cancel the IRN within 24 hours and reissue. After 24 hours, you must use a credit note.
Train your invoicing team. Ensure the accounts team understands what e-invoicing is, why IRN is mandatory, and what to do when errors occur. The GST invoicing module in ERPDrive makes this straightforward, but team awareness is still important.
Keep API credentials secure. If you use API-based e-invoice generation (which ERPDrive provides), ensure the API credentials are stored securely and access is limited to authorised personnel.

Conclusion

GST e-invoicing is a compliance requirement that manufacturers cannot ignore. With the turnover threshold now at INR 5 crore and likely to decrease further, even small and mid-size manufacturers need a reliable e-invoice generation process. The most efficient approach is to use a manufacturing ERP with built-in IRP integration, which eliminates manual portal visits, reduces errors, ensures timely IRN generation, and automatically handles e-way bills and GSTR-1 population.

ERPDrive's GST invoicing module handles e-invoice generation, e-way bills, credit notes, and all GST return reports from a single platform. If your factory is still generating e-invoices manually through the portal, book a free demo and see how much time you can save with automated compliance.