GST & business

How to Create a GST Invoice: Mandatory Fields and Steps

Updated 25 September 2026 · 5 min read

If you're registered under GST and sell taxable goods or services, you must issue a tax invoice. Your buyer needs a correct one to claim input tax credit — a missing GSTIN or wrong state can cost them the credit, and you the customer.

What a GST invoice must contain

1. Your name, address and GSTIN
2. A unique invoice number (up to 16 characters, in one series per financial year) and the invoice date
3. The buyer's name and address, and their GSTIN if they're registered
4. Place of supply (state name and code) — decides CGST + SGST vs IGST
5. Description, HSN code (goods) or SAC code (services), quantity and unit
6. Taxable value, after any discount
7. GST rate and amount, shown separately as CGST + SGST, or IGST
8. Total invoice value, in figures and words
9. Whether tax is payable under reverse charge
10. Signature or digital signature of the supplier

How to make one in a few minutes

1. Open the invoice generator and enter your business details once — they're remembered for next time.
2. Add the buyer and their GSTIN. Check the GSTIN first — a typo breaks the buyer's tax credit.
3. Pick the place of supply. The tool applies CGST + SGST for the same state and IGST otherwise.
4. Add items with HSN/SAC, quantity, rate and GST rate. Totals and the amount in words fill in automatically.
5. Optionally add your logo and a UPI QR code so the customer can pay instantly, then download the PDF.

Common mistakes

• Charging IGST on a same-state sale (or CGST + SGST across states) — the buyer can't claim the credit and you have to amend.
• Skipping invoice numbers or reusing one within the year.
• Calculating GST on the inclusive price — see GST calculation examples.

Want a layout to copy? See the GST invoice format for small businesses.

Frequently asked questions