Gst Invoice Generator

GST Invoice Generator: Complete Guide for Indian Businesses (2025)

The Goods and Services Tax (GST) revolutionized the Indian taxation system when it was introduced on July 1, 2017. One of the most critical compliance requirements under GST is the generation of proper tax invoices. A GST-compliant invoice is not just a bill — it is a legal document that enables the buyer to claim Input Tax Credit (ITC) and helps both parties stay compliant with GST laws.

Whether you are a small business owner, a freelancer, or a large enterprise, understanding the GST invoice format, mandatory fields, and compliance requirements is essential. This comprehensive guide covers everything you need to know about generating GST invoices, including the format, rules for different business types, HSN/SAC codes, e-invoicing, and how to use our GST invoice generator to create professional invoices instantly.

What is a GST Invoice?

A GST invoice is a document issued by a registered supplier to the recipient, listing the goods or services supplied, their quantities, prices, and the GST charged. Under the GST law, every registered dealer must issue a tax invoice for every sale of goods or services. The invoice serves multiple purposes:

• Evidence of Supply: Proof that a transaction has taken place between the supplier and recipient.
• Claiming Input Tax Credit: The recipient (buyer) can claim ITC only if they possess a valid GST invoice from the supplier.
• GST Return Filing: The details of invoices are required to be furnished in GST returns (GSTR-1, GSTR-3B, etc.).
• Legal Record: In case of audits or inspections by GST authorities, invoices serve as primary evidence of transactions.

Mandatory Fields in a GST Invoice

As per Rule 46 of the CGST Rules, 2017, a tax invoice must contain the following mandatory fields:

• Invoice Number: A unique serial number (up to 16 characters) containing alphabets, numerals, or special characters — sequential for each financial year.
• Invoice Date: The date of issuance of the invoice.
• Supplier Details: Name, address, and GSTIN of the supplier.
• Recipient Details: Name, address, and GSTIN of the recipient (if registered). For unregistered recipients, name and address are sufficient.
• Place of Supply: The state where the goods or services are being delivered.
• HSN/SAC Code: HSN (Harmonized System of Nomenclature) for goods or SAC (Service Accounting Code) for services.
• Description: Description of the goods or services supplied.
• Quantity and Unit: Quantity of goods (in applicable units) or nature of service.
• Taxable Value: Value of goods or services before GST.
• Rate of Tax: CGST, SGST/UTGST, and IGST rates applicable.
• Amount of Tax: Tax amount in rupees for CGST, SGST/UTGST, and IGST separately.
• Total Invoice Value: Total amount payable (taxable value + taxes).
• Amount in Words: Total invoice value in words.
• Signature/Digital Signature: Signature of the supplier or authorized representative (digital signature for e-invoices).
• QR Code: For B2C invoices with value exceeding ₹500 (optional for other cases).

GST Invoice Formats by Business Type

1. B2B Invoice (Registered Buyer)

When selling to a GST-registered buyer, the invoice must include:

• GSTIN of both supplier and recipient
• Place of Supply (to determine IGST or CGST+SGST applicability)
• Separate columns for CGST and SGST/UTGST or IGST
• HSN/SAC codes at minimum 4-digit level (or 6/8-digit as per notification)
• Invoice value breakup

2. B2C Invoice (Unregistered Buyer)

When selling to an unregistered customer, the invoice must include:

• Supplier's GSTIN and name/address
• Buyer's name and address (if available)
• Place of Supply (the state of delivery)
• QR code if invoice value exceeds ₹500
• Tax breakup (CGST, SGST, or IGST)

3. Composition Scheme Invoice

Businesses registered under the Composition Scheme must issue a bill of supply instead of a tax invoice. A bill of supply does not contain separate tax details. It must include:

• The words 'Bill of Supply' prominently displayed
• Supplier's name, address, and GSTIN
• Date and a unique serial number
• Description of goods/services
• Total amount payable
• HSN/SAC code
• A declaration: "Cannot collect tax as registered under Composition Scheme"

4. Reverse Charge Invoice

If the recipient is liable to pay GST under reverse charge, the invoice must be issued by the recipient (not the supplier). The reverse charge invoice must include all mandatory fields plus a declaration that the tax is payable under reverse charge.

HSN and SAC Codes

HSN (Harmonized System of Nomenclature) codes are used for goods, while SAC (Service Accounting Code) codes are used for services. Under GST, the requirement for mentioning HSN/SAC codes is based on the turnover of the supplier:

Turnover	HSN/SAC Code Requirement
Up to ₹5 crore in preceding year	4-digit HSN/SAC code mandatory
Above ₹5 crore in preceding year	6-digit HSN/SAC code mandatory
Export/Import	8-digit HSN code mandatory

GST Tax Rates in India (2025)

The GST Council has classified goods and services into four main tax slabs:

• 5% GST: Essentials like packaged food items, apparel below ₹1,000, medicines, railway/air travel (economy), etc.
• 12% GST: Processed food, computers, mobile phones, business class air travel, etc.
• 18% GST: Most goods and services fall under this slab — IT services, telecom, banking, AC restaurants, etc.
• 28% GST: Luxury items, sin goods — automobiles, tobacco, aerated drinks, luxury hotels, etc.
• 0% (Nil): Essential items like fresh vegetables, milk, eggs, bread, salt, education, healthcare, etc.

CGST, SGST, and IGST

Understanding the type of GST applicable is crucial for correct invoice generation:

• Intra-State Supply (within same state): CGST (Central GST) + SGST (State GST) — both at half the total GST rate. For example, if the GST rate is 18%, CGST = 9% and SGST = 9%.
• Inter-State Supply (different states): IGST (Integrated GST) — at the full GST rate. For example, if the rate is 18%, IGST = 18%.
• Union Territories: CGST + UTGST (Union Territory GST) instead of SGST for supplies to UT territories.
• Exports: Zero-rated supply — can be made under bond/LUT without payment of IGST, or with payment of IGST and subsequent refund claim.

E-Invoicing Under GST

E-invoicing (electronic invoicing) was introduced by the GST Council to standardize invoice formats and enable real-time reporting. Under e-invoicing, invoices generated by businesses are authenticated by the Invoice Registration Portal (IRP) and assigned a unique Invoice Reference Number (IRN).

Who Needs E-Invoicing?

As of 2025, e-invoicing is mandatory for businesses with aggregate turnover exceeding ₹5 crore in any preceding financial year from FY 2023-24. The threshold was gradually reduced from ₹500 crore (Oct 2020) to ₹100 crore (Jan 2021), ₹50 crore (April 2021), ₹20 crore (April 2022), ₹10 crore (Oct 2022), and finally ₹5 crore.

E-Invoicing Process

1. Generate the invoice in your accounting/billing software (in the standard JSON format).
2. Upload the invoice JSON to the Invoice Registration Portal (IRP).
3. The IRP validates the invoice, generates a unique Invoice Reference Number (IRN), and returns a digitally signed JSON with a QR code.
4. Print the QR code on the invoice copy.
5. The invoice is reported to the GST system for auto-populating GSTR-1.

Benefits of E-Invoicing

• Auto-population of Returns: GSTR-1 gets auto-populated from e-invoices.
• Reduced Errors: Validation by the IRP ensures data accuracy.
• Faster ITC Claim: Buyers can claim ITC instantly as invoices are reported in real-time.
• Anti-Evasion: Real-time reporting reduces tax evasion.
• No Manual Data Entry: Saves time and reduces reconciliation issues.

GST Invoice for E-Commerce Operators

E-commerce operators (Amazon, Flipkart, etc.) have special GST invoicing rules:

• The e-commerce operator must issue an invoice for supplies made through their platform.
• TDS under Section 52 is deducted by the e-commerce operator at 1% (CGST 0.5% + SGST 0.5% or IGST 1%).
• E-commerce operators must include their GSTIN and the seller's details on the invoice.
• The place of supply rules for e-commerce transactions are specific — typically the buyer's delivery address.

How to Use a GST Invoice Generator

Our GST invoice generator at toolsofindia.com makes it simple to create professional, GST-compliant invoices. Here is how to use it:

Step 1: Enter Business Details

• Your business
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