How should I number my GST invoices?

In a single consecutive series for each financial year, up to 16 characters, using letters, numbers, hyphens or slashes, such as INV/26-27/001.

Is a signature required on a GST invoice?

Yes, the supplier or an authorised person must sign it, by hand or with a digital signature.

What is the place of supply?

The state where the supply is treated as made, usually where the goods are delivered or, for services, the buyer's location. It decides whether you charge IGST or CGST and SGST.

GST invoice format: what a tax invoice must include (with CGST, SGST and IGST)

Updated 23 September 2026

A GST tax invoice can only be issued by a GST-registered business. It must show your details and GSTIN, a unique invoice number and date, the buyer's details, the place of supply, each item with its HSN or SAC code, the taxable value, the GST rate and amount (CGST and SGST, or IGST), the total, and a signature.

What must a GST invoice include?

Your name, address and GSTIN.
A consecutive invoice number, unique for the financial year, of up to 16 characters.
The date of issue.
The buyer's name and address, and their GSTIN if they're registered.
The place of supply, with the state name, for supplies to another state.
For each item: description, HSN (goods) or SAC (services) code, quantity and unit, and taxable value after any discount.
The GST rate and the amount of each tax: CGST and SGST/UTGST, or IGST.
The total value, and whether tax is payable under reverse charge.
Your signature or digital signature.

When do I charge CGST and SGST, and when IGST?

Compare your state (the first two digits of your GSTIN) with the place of supply. If they're the same, it's an intra-state supply: charge CGST and SGST, each at half the rate (9% + 9% for 18%). If they're different, charge IGST at the full rate.

How many digits of HSN code do I need?

With turnover up to ₹5 crore in the previous year, at least 4 digits on invoices to registered buyers. Above ₹5 crore, 6 digits on every tax invoice.

What are the GST rates now?

From 22 September 2025 the main slabs are 5% and 18%, with 40% for a small list of luxury and "sin" goods, and nil for exempt essentials. Gold and silver are at 3% and rough diamonds at 0.25%. Check the rate for your exact HSN or SAC code.