GST invoice format: every field your bill must have

A GST invoice is not just a bill. It is the document your customer uses to claim input tax credit and the document tax officers check first. A missing field can cost your customer their credit and cost you the customer.

You can make a compliant invoice in a minute with our free invoice generator. Here is what goes into it and why.

Tax invoice or bill of supply?

• Issue a tax invoice when you are a regular GST-registered business selling taxable goods or services.
• Issue a bill of supply when you are under the composition scheme, or when you sell only exempt goods or services. A bill of supply shows no GST.
• A receipt voucher is issued when you receive an advance, and a credit note or debit note adjusts an invoice already issued.

The mandatory fields on a tax invoice

1. Your name, address and GSTIN.
2. An invoice number: consecutive, unique for the financial year, up to 16 characters, using letters, numbers, hyphens or slashes. For example BK/26-27/0145.
3. Date of issue.
4. Customer's name and address.
5. Customer's GSTIN, if they are registered.
6. For an unregistered customer with a value of ₹50,000 or more, the delivery address with state name and state code.
7. HSN code for goods or SAC code for services.
8. Description of the goods or services.
9. Quantity and unit, such as kg, pcs or box.
10. Total value of the supply.
11. Taxable value after any discount.
12. GST rate and amount, split into CGST and SGST, or shown as IGST.
13. Place of supply, with the state name, for inter-state supplies.
14. Whether tax is payable on reverse charge.
15. Signature or digital signature of the supplier or authorised person.

How many HSN digits?

A sample layout

Amount in words: Rupees Ten Thousand Thirty only. Our amount-in-words tool writes this line for any figure in the Indian lakh and crore system.

Copies of the invoice

For goods, prepare three copies: the original for the buyer, the duplicate for the transporter, and the triplicate for your own records. For services, two copies: original for the customer, duplicate for you.

When to issue the invoice

• Goods: on or before removal of goods for delivery, or delivery itself.
• Services: within 30 days of providing the service. Banks and some financial services have longer periods.

If your turnover is above ₹5 crore

B2B invoices must be reported on the government's Invoice Registration Portal to get an IRN and a signed QR code. This is e-invoicing. Below that threshold, a well-prepared invoice from any tool, including ours, is enough.

Mistakes that cost customers their input tax credit

• Wrong or missing customer GSTIN.
• CGST and SGST charged on an inter-state sale instead of IGST.
• Invoice numbers that repeat or skip in the same year.
• Rate not matching the HSN code.
• Invoice not reported in your GSTR-1, so it never reaches the customer's GSTR-2B.

Check a customer's GSTIN format before billing with our GSTIN checker.

Common questions

This guide is general information to help you understand the topic. It is not legal, tax or financial advice. Rules and rates change; confirm details for your situation with a qualified professional or the official government portal. Read our editorial policy.