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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

TypeWhen to Use
Tax InvoiceStandard GST invoice for registered businesses
Bill of SupplyWhen GST is not applicable (exempted goods/services)
Credit NoteTo reduce a previous invoice amount (returns, discounts)
Debit NoteTo increase a previous invoice amount
Proforma InvoiceQuote before actual supply (not a legal GST document)

How to Create a GST Invoice Free Online

  1. Go to Toolkiya Invoice Generator
  2. Enter your business name, GSTIN, and address
  3. Add buyer details
  4. Add line items with HSN codes, quantity, and rate
  5. Select GST rate — CGST+SGST or IGST is calculated automatically
  6. Preview and download as PDF — ready to print or email

No data stored. No subscription. Unlimited invoices, free forever.

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