GST Invoice Format: Mandatory Fields Checklist for Small Businesses

If your business is registered under GST, every sale needs a proper tax invoice. A missing field can cause trouble for your customer's input tax credit, and for you during an audit. Here is a plain checklist.

Mandatory fields on a GST tax invoice

1. Supplier's name, address and GSTIN.
2. Invoice number: unique and consecutive, up to 16 characters (letters, numbers, "-" or "/"), unique for each financial year.
3. Date of issue.
4. Recipient's name and address, and their GSTIN if they are registered.
5. Place of supply, with the state name and state code, for interstate supplies.
6. HSN code for goods or SAC code for services.
7. Description of goods or services.
8. Quantity and unit (for goods).
9. Total value and taxable value, after any discount.
10. GST rate and amount, shown separately as CGST + SGST, or IGST.
11. Whether tax is payable on reverse charge.
12. Signature (or digital signature) of the supplier or authorised person.

CGST + SGST or IGST?

• Same state (seller and place of supply in the same state): charge CGST + SGST, each at half the GST rate. Example: 18% becomes 9% CGST + 9% SGST.
• Different states: charge IGST at the full rate.

The first two digits of a GSTIN are the state code (for example, 06 is Haryana and 08 is Rajasthan), which makes it easy to check.

Current GST rates

Since 22 September 2025, most goods and services fall under 0%, 5%, 18%, with 40% for a small set of luxury and sin goods. Restaurant food is usually 5%. Always confirm the rate for your specific HSN or SAC code.

Tax invoice vs bill of supply vs quotation

• Tax invoice: issued by registered businesses when they charge GST.
• Bill of supply: issued instead of a tax invoice by composition-scheme businesses or for exempt supplies, because no GST is charged.
• Quotation: an offer sent before the sale, not a tax document. Make one with the free Quotation Maker.

Large businesses: e-invoicing

Businesses above the e-invoicing turnover limit (currently ₹5 crore) must generate e-invoices through the government portal. Smaller businesses can keep issuing regular invoices.

Create a GST invoice for free

The free GST Invoice Generator includes every field above, picks CGST + SGST or IGST from the GSTIN automatically, adds your logo, and prints a clean invoice or saves it as PDF. No sign-up. For cafés and restaurants billing all day, CafeCorp handles GST billing at the counter.

This article is general guidance. Confirm GST rules for your business with your accountant.