E-Invoice Guide 2025-26: Everything You Need to Know About GST E-Invoicing

E-invoicing has become one of the most significant compliance requirements under GST in India. Whether you're a small business owner in Mumbai or a chartered accountant managing multiple clients across Maharashtra, understanding e-invoicing is no longer optional — it's essential. This comprehensive e-invoice guide covers everything from applicability and turnover limits to the step-by-step process of generating e-invoices in FY 2025-26.

At Mark IT Solutions, a Tally 5-Star Certified Partner in Mumbai, we've helped hundreds of businesses transition to e-invoicing smoothly. Let's break down what you need to know.

What Is E-Invoicing Under GST?

E-invoicing (electronic invoicing) is a system where B2B invoices are authenticated electronically by the GST Network (GSTN) through the Invoice Registration Portal (IRP). When you generate an e-invoice, the IRP assigns a unique Invoice Reference Number (IRN) and a digitally signed QR code to your invoice.

It's important to understand that e-invoicing doesn't mean generating invoices on a government portal. You still create invoices in your billing software (like Tally Prime) — the system simply reports them to the IRP for validation and authentication.

Key Components of an E-Invoice

• IRN (Invoice Reference Number): A unique 64-character hash assigned to each invoice
• QR Code: Contains key invoice details for quick verification
• Digital Signature: Ensures the invoice hasn't been tampered with
• JSON Format: The standard data format used for IRP communication

E-Invoice Applicability: Who Needs to Generate E-Invoices?

The applicability of e-invoicing depends on your aggregate annual turnover. The government has been progressively lowering the threshold since its introduction in 2020.

Current E-Invoice Turnover Limits (FY 2025-26)

Important: The turnover threshold is based on aggregate turnover in any preceding financial year from 2017-18 onwards. If your business exceeded the threshold even once, e-invoicing applies to you going forward.

Not sure if e-invoicing applies to your business? Use our free E-Invoice Eligibility Checker to find out instantly.

Who Is Exempt from E-Invoicing?

• SEZ Units (not SEZ developers)
• Insurance companies and banking companies
• Financial institutions including NBFCs
• Goods Transport Agencies (GTAs)
• Passenger transportation services
• Admission to exhibition of cinematograph films

How to Generate E-Invoices: Step-by-Step Process

Generating e-invoices is straightforward once you understand the workflow. Here's a detailed walkthrough:

Step 1: Register on the E-Invoice Portal

1. Visit the E-Invoice Portal (einvoice1.gst.gov.in)
2. Click on "Registration" and select "e-Invoice Enablement"
3. Enter your GSTIN and verify with OTP
4. Complete the registration process

Pro Tip: Validate your GSTIN before registration using our free GSTIN Validator.

Step 2: Configure Your Billing Software

If you're using Tally Prime (which we recommend and support as a certified partner), e-invoicing is built-in:

1. Open Gateway of Tally → press F11 (Features)
2. Enable GST e-Invoice under Statutory & Taxation
3. Enter your Signer credentials
4. Configure your API credentials from the IRP portal

Step 3: Generate the Invoice in Your Software

Create your regular sales invoice in Tally Prime with all mandatory fields:

• Supplier and recipient GSTIN
• Invoice number and date
• HSN codes for all items (use our HSN Code Finder if needed)
• Item-wise taxable value and GST rates
• Place of supply and GST state codes

Step 4: Push to IRP for Authentication

1. From Tally, select the invoice and click "Generate e-Invoice"
2. The software sends the invoice JSON to the IRP
3. The IRP validates the data, generates the IRN, and returns the signed invoice
4. The QR code and IRN are automatically embedded in your invoice

Step 5: Share the Authenticated Invoice

The e-invoice is now valid and can be shared with your buyer. The IRP also auto-populates your GSTR-1 with the reported invoices, reducing manual data entry.

E-Invoice in Tally Prime: Why It's the Best Choice

As a Tally 5-Star Certified Partner, we've seen firsthand how Tally Prime simplifies e-invoicing for businesses:

• One-Click Generation: Generate e-invoices directly from your sales voucher
• Bulk Generation: Process multiple invoices in a single batch
• Auto-Population: GSTR-1 data is pre-filled from e-invoices
• Error Handling: Clear error messages when IRP rejects an invoice
• Cancel & Amend: Cancel e-invoices within 24 hours directly from Tally

If you need help setting up e-invoicing in Tally Prime, contact our team for expert assistance.

Common E-Invoice Errors and How to Fix Them

Error: "Duplicate IRN"

Cause: An invoice with the same number, date, and GSTIN combination already exists.
Fix: Check if the invoice was already reported. If you need to regenerate, cancel the existing IRN first.

Error: "Invalid GSTIN"

Cause: The buyer or supplier GSTIN is incorrect or inactive.
Fix: Verify the GSTIN using our GSTIN Validator before creating invoices.

Error: "HSN Code Not Found"

Cause: The HSN code used doesn't exist in the master database.
Fix: Look up the correct HSN code using our HSN Code Finder.

Error: "Invoice Date Cannot Be Older Than 30 Days"

Cause: As of November 2023, e-invoices cannot be generated for invoices older than 30 days.
Fix: Ensure timely reporting of all B2B invoices. Read our 30-day e-invoice reporting rule guide.

E-Invoice Penalties for Non-Compliance

• Penalty of ₹10,000 per invoice or 100% of the tax due (whichever is higher) under Section 122 of the CGST Act
• Disallowance of Input Tax Credit (ITC) for the buyer
• The invoice may be treated as an invalid document for GST purposes
• Repeated non-compliance may attract assessment and audit by GST authorities

E-Invoicing Best Practices for Mumbai Businesses

1. Maintain accurate master data — Ensure all GSTINs, HSN codes, and addresses are updated
2. Generate e-invoices in real-time — Don't batch invoices beyond a day to avoid the 30-day limit
3. Use Tally Prime's bulk generation — For high-volume businesses, batch processing saves hours
4. Keep API credentials secure — Don't share IRP login details across multiple users
5. Reconcile regularly — Match e-invoice data with GSTR-1 and GSTR-2B monthly
6. Calculate GST accurately — Use our GST Calculator to verify tax amounts before invoicing

Need help with e-invoicing setup or Tally Prime? Contact Mark IT Solutions — Mumbai's trusted Tally partner. Check your e-invoice eligibility with our free tool, or explore our Tally support services for ongoing compliance assistance.