Free Invoice Generator India — GST Invoice Format & Online Tool (2026)
Every business registered under GST in India must issue a proper tax invoice. This guide covers the mandatory fields, legal rules under GST, and how to generate one free in under 2 minutes.
What is a GST Invoice?
A GST (Goods and Services Tax) invoice is an official document issued by a GST-registered supplier to a buyer for the supply of goods or services. It serves as the primary document for claiming Input Tax Credit (ITC) and is a legal requirement under the CGST Act, 2017.
If your annual turnover exceeds ₹20 lakhs (₹10 lakhs for special category states), you must be GST registered and issue proper tax invoices.
Mandatory Fields in a GST Invoice
As per Rule 46 of CGST Rules, 2017, a tax invoice must contain:
Supplier Details
- Name, address, and GSTIN of the supplier
- Invoice number (consecutive, unique per financial year)
- Invoice date
Recipient Details
- Name and address of the buyer
- GSTIN of the buyer (for B2B transactions)
- State name and code
- Place of supply
Item-wise Details
- Description of goods or services
- HSN code (for goods) or SAC code (for services)
- Quantity and unit
- Unit price (taxable value)
- Discount (if any)
- Total taxable value
Tax Details
- Applicable GST rate
- CGST + SGST (for intra-state supply) or IGST (for inter-state supply)
- Tax amount per line item
- Total tax amount
Other Required Fields
- Total invoice value (in figures and words)
- Whether GST is payable on reverse charge basis
- Signature of the supplier
GST Invoice Rules You Must Know
- Invoice timing: Must be issued within 30 days of supply of service (45 days for banking sector)
- Invoice numbering: Must be sequential and unique within a financial year. Cannot reuse numbers.
- Original + copy: Three copies required — Original for buyer, Duplicate for transporter, Triplicate for supplier
- Digital invoices: E-invoices are mandatory for businesses with turnover above ₹5 crores from August 2023
- HSN code requirement: HSN code mandatory for turnover above ₹5 crores (6-digit), above ₹1.5 crore (4-digit)
Types of GST Invoices
| Type | When to Use |
|---|---|
| Tax Invoice | Standard GST invoice for registered businesses |
| Bill of Supply | When GST is not applicable (exempted goods/services) |
| Credit Note | To reduce a previous invoice amount (returns, discounts) |
| Debit Note | To increase a previous invoice amount |
| Proforma Invoice | Quote before actual supply (not a legal GST document) |
How to Create a GST Invoice Free Online
- Go to Toolkiya Invoice Generator
- Enter your business name, GSTIN, and address
- Add buyer details
- Add line items with HSN codes, quantity, and rate
- Select GST rate — CGST+SGST or IGST is calculated automatically
- Preview and download as PDF — ready to print or email
No data stored. No subscription. Unlimited invoices, free forever.
Built & maintained by Mayank Rai
Solo developer based in Lucknow, India · Last updated April 3, 2026
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