
How to Create a GST Invoice in India - Complete Guide with Examples (2026)
What is a GST invoice and why does it matter?
A GST invoice is a legal document issued by a registered supplier when selling goods or services. Under the Goods and Services Tax Act, 2017, every registered business must issue a tax invoice for taxable supplies. This invoice serves as proof of the transaction and is the primary document the buyer needs to claim Input Tax Credit (ITC).
Without a proper GST invoice, the buyer cannot claim ITC, which means they end up paying more tax than necessary. For the seller, not issuing a proper invoice can lead to penalties under Section 122 of the CGST Act, up to Rs. 10,000 or the amount of tax involved, whichever is higher. This is why getting your invoice format right is essential, whether you are a freelancer, a shop owner, or running a small business.
There are three types of GST invoices: Tax Invoice (for taxable supplies), Bill of Supply (for exempt supplies or composition scheme dealers), and Revised Invoice (for corrections). This guide focuses on the Tax Invoice, which is the most commonly used format.
16 mandatory fields every GST invoice must have
According to Rule 46 of the CGST Rules, a tax invoice must contain these fields: (1) Name, address and GSTIN of the supplier. (2) A consecutive serial number unique to a financial year, this can be alphanumeric like INV-2026-001. (3) Date of issue. (4) Name, address and GSTIN/UIN of the recipient if registered. (5) Name and address of the recipient if unregistered and the invoice value exceeds Rs. 50,000.
(6) HSN code of goods or SAC code of services. (7) Description of goods or services. (8) Quantity of goods and unit of measurement. (9) Total value of supply. (10) Taxable value after discounts. (11) Rate of tax: CGST, SGST/UTGST and IGST rates separately. (12) Amount of tax: CGST, SGST and IGST amounts separately. (13) Place of supply along with state name and code. (14) Whether tax is payable on reverse charge basis. (15) Signature or digital signature of the supplier. (16) QR code for invoices with value above Rs. 500 crore turnover.
For small businesses with turnover below Rs. 5 crore, a 4-digit HSN code is sufficient. Businesses above Rs. 5 crore need 6-digit HSN codes. If your turnover is below Rs. 1.5 crore, HSN code is optional but recommended for clarity.
CGST + SGST vs IGST: when to apply which tax
This is one of the most common points of confusion. The rule is straightforward: if the place of supply is in the same state as the seller, you charge CGST + SGST (each at half the total GST rate). If the place of supply is in a different state, you charge IGST (at the full GST rate).
Example: You are a web designer based in Maharashtra (GSTIN: 27XXXXX). You invoice a client in Maharashtra for Rs. 1,00,000. GST rate for IT services is 18%. Since both parties are in the same state, you charge CGST at 9% (Rs. 9,000) + SGST at 9% (Rs. 9,000). Total invoice: Rs. 1,18,000.
Now, if the same client were in Karnataka, you would charge IGST at 18% (Rs. 18,000) instead. Total invoice would still be Rs. 1,18,000, but the tax breakup would show only IGST. The place of supply for services is generally the location of the recipient. For goods, it is the place of delivery.
Real invoice example: Rs. 50,000 supply with HSN codes
Let us walk through a complete example. Suppose you sell printed t-shirts from Delhi to a buyer in Delhi. You sell 100 t-shirts at Rs. 500 each. HSN code for printed t-shirts is 6109. GST rate is 5% (for garments below Rs. 1,000 per piece).
Invoice calculation: Taxable value = 100 x Rs. 500 = Rs. 50,000. Since both seller and buyer are in Delhi (same state): CGST at 2.5% = Rs. 1,250. SGST at 2.5% = Rs. 1,250. Grand total = Rs. 52,500.
Your invoice would list: Item description: 'Printed cotton t-shirts', HSN: 6109, Qty: 100, Rate: Rs. 500, Amount: Rs. 50,000, CGST 2.5%: Rs. 1,250, SGST 2.5%: Rs. 1,250, Total: Rs. 52,500. This is exactly the format most accounting software and tax authorities expect.
Common GST invoice mistakes and how to avoid them
Mistake 1: Wrong place of supply. If you select the wrong state, you will charge the wrong tax type (CGST+SGST vs IGST). This creates problems during GST return filing as the tax credit will not match between the buyer and seller.
Mistake 2: Missing or incorrect HSN/SAC codes. From April 2021, HSN codes became mandatory on invoices based on turnover thresholds. Using the wrong code can lead to tax mismatches during assessment.
Mistake 3: Non-sequential invoice numbers. Invoice numbers must be consecutive within a financial year. Gaps or duplicates can trigger scrutiny during audits. Use a consistent format like 'INV-2026-0001' and maintain a register.
Mistake 4: Not mentioning 'Tax is payable on reverse charge' when applicable. For certain services (like legal services from an advocate, or transport by a GTA), the recipient pays the tax, not the supplier. This must be clearly stated on the invoice.
How to create a GST invoice online, step by step
If you do not use accounting software like Tally or Zoho, you can create professional GST invoices using free online tools. Open a GST invoice generator, enter your business details (name, address, GSTIN), add the buyer details, select the place of supply, and add line items with HSN code, quantity, rate, and GST percentage.
The tool should automatically split the tax into CGST+SGST or IGST based on the place of supply. Review the live preview to ensure all details are correct, then download the PDF. Print a copy for your records, and send the digital copy to your buyer via email or WhatsApp.
For official GST return filing (GSTR-1, GSTR-3B), always enter the same invoice details into the GST portal. The invoice you generate is for record-keeping and sharing with the buyer. Your CA or tax advisor should confirm the format before you file returns based on these invoices.
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