A GST Invoice is a document issued by a registered supplier to the buyer during the sale of goods or services. It is a mandatory document under the Goods and Services Tax (GST) regime in India and serves as proof of supply.
Whether you run a small kirana store or a large manufacturing unit, understanding GST invoices is essential for tax compliance and smooth business operations.
Why is a GST Invoice Important?
- Legal requirement: Every GST-registered business must issue a tax invoice for every sale.
- Input Tax Credit (ITC): Buyers need a valid GST invoice to claim ITC on their purchases.
- Record keeping: Invoices serve as proof of transactions for audits and returns.
- Dispute resolution: Clear invoices prevent misunderstandings between buyer and seller.
Types of GST Invoices
1. Tax Invoice
Issued by a registered supplier for taxable goods or services. This is the most common type of GST invoice.
2. Bill of Supply
Issued when selling exempt goods/services or by a composition scheme dealer. No tax is charged on a Bill of Supply.
3. Receipt Voucher
Issued when advance payment is received before the supply of goods or services.
4. Credit Note
Issued when the taxable value or tax charged is more than the actual amount, or when goods are returned.
5. Debit Note
Issued when the taxable value or tax charged is less than the actual amount.
Mandatory Fields in a GST Invoice
Every GST invoice must contain these fields:
- Name, address, and GSTIN of the supplier
- A consecutive serial number (unique for each financial year)
- Date of issue
- Name, address, and GSTIN of the buyer (if registered)
- HSN code of goods or SAC code of services
- Description of goods or services
- Quantity of goods and unit of measurement
- Total value of supply
- Taxable value after discounts
- Rate of tax (CGST, SGST, IGST)
- Amount of tax charged
- Place of supply (for inter-state transactions)
- Signature or digital signature of the supplier
When Must You Issue a GST Invoice?
| Type of Supply | Time Limit |
|---|---|
| Supply of Goods | Before or at the time of removal/delivery |
| Supply of Services | Within 30 days of supply |
| Continuous Supply (Goods) | Before or at the time of each statement/payment |
| Continuous Supply (Services) | Before due date of payment |
GST Invoice Format — Sample
A standard GST invoice typically includes:
Sample Invoice Header
Invoice No: INV-2026-001
Date: April 18, 2026
Supplier: ABC Traders, GSTIN: 27AAACB1234F1Z5
Buyer: XYZ Enterprises, GSTIN: 29AABCX5678G1Z3
Place of Supply: Karnataka (29)
How to Create a GST Invoice with BillCraft
- Open BillCraft on your phone or computer
- Enter your business details and GSTIN
- Add buyer information
- Add items with HSN codes, quantities, and GST rates
- BillCraft auto-calculates CGST, SGST, or IGST based on the place of supply
- Download the PDF and share via WhatsApp or email
Pro Tip
Save your business details in BillCraft once, and they auto-fill on every new invoice. This saves time and reduces errors.
Common GST Invoice Mistakes to Avoid
- Missing or incorrect GSTIN
- Wrong HSN/SAC codes
- Not mentioning the place of supply
- Incorrect tax calculation (applying IGST instead of CGST+SGST)
- Duplicate invoice numbers
Conclusion
A GST invoice is more than just a bill — it's a legal document that ensures tax compliance and enables Input Tax Credit. With BillCraft, you can create GST-compliant invoices in seconds, right from your mobile phone.