Home / Guides

GST invoice format: every field you need

Updated 10 November 2026

Your customer can only claim input tax credit if your invoice is right, so a missing field is their problem first and then yours. Rule 46 of the CGST Rules, 2017 sets out what a tax invoice must show. Blogs count the fields differently, from 13 up to 21, because they group them differently. The count does not matter. This is the list.

The checklist

• Your name, address and GSTIN
• The words "Tax Invoice"
• An invoice number in one continuous series for the financial year, up to 16 characters, using letters, numbers, hyphens or slashes
• The date of issue
• The buyer's name, address and GSTIN, if registered
• Place of supply, with the state name and code, for inter-state sales
• Delivery address, if different from the billing address
• HSN code for goods or SAC code for services
• Description, quantity and unit
• Total value, discount and taxable value
• Tax rate, and the amount of CGST, SGST or IGST shown separately
• Whether tax is payable on reverse charge
• Your signature or digital signature

How many HSN digits

This depends on your aggregate turnover in the previous financial year, under Notification 78/2020-Central Tax.

CGST and SGST, or IGST

Look at where the sale happens. If you and the place of supply are in the same state, split the tax into CGST and SGST. If they are in different states, charge IGST. On a taxable value of ₹10,000 at 18%:

The total is the same either way. Getting the split wrong can still mean paying the correct tax again under the correct head and claiming the wrong one back.

When to issue it

• Goods: at or before the time you remove them for delivery, or deliver them.
• Services: within 30 days of supplying the service. Banks and similar financial businesses get 45 days.

How many copies

For goods, make three: the original for the buyer, the duplicate for the transporter and the triplicate for you. For services, make two: the original for the buyer and the duplicate for you.

Sales to people who are not registered

If the buyer is unregistered and the taxable value is ₹50,000 or more, also show their name, address, delivery address, and the state name and code. For sales under ₹200 to an unregistered buyer who does not ask for an invoice, you can issue one consolidated invoice at the end of the day.

When a normal invoice is not enough

Businesses above the e-invoicing turnover limit, currently ₹5 crore, must get each B2B invoice registered on the government portal, which gives it an IRN and QR code. DeskKit does not do this. Composition dealers issue a bill of supply, which carries no tax amount.

Mistakes that cost money

• Restarting or skipping numbers partway through the year. Start a new series each April instead.
• Copying the buyer's GSTIN by hand and getting one character wrong. The buyer's credit fails to show.
• Using last year's rate after a rate change.
• Showing one combined "GST" amount in place of the separate heads.

Sources

• CGST Act, 2017, section 31
• CGST Rules, 2017, rules 46, 47 and 48
• Notification 78/2020-Central Tax, 15 October 2020, on HSN digits

This is general information, not tax advice. GST rules change, so check anything important with your accountant.