GST Invoice Format: Mandatory Fields Under Rule 46 (with Checklist)

A GST invoice isn't just a bill. It is the document your customer relies on to claim input tax credit, so missing fields can cost them money — and cost you a customer. Rule 46 of the CGST Rules lists what a tax invoice must contain.

Mandatory fields on a tax invoice

1. Supplier's name, address and GSTIN.
2. Invoice number — consecutive, unique for the financial year, up to 16 characters (letters, numbers, - and /).
3. Date of issue.
4. Recipient's name, address and GSTIN (if registered).
5. For unregistered recipients where the taxable value is ₹50,000 or more: name, address, delivery address, and state name with state code.
6. HSN code for goods or SAC for services (see digit rules below).
7. Description of goods or services.
8. Quantity and unit (for goods).
9. Total value of supply.
10. Taxable value after discounts or abatement.
11. Rate of tax — CGST, SGST/UTGST, IGST and cess, as applicable.
12. Amount of tax for each of those.
13. Place of supply with state name, for inter-state supplies.
14. Delivery address, where different from the place of supply.
15. Whether tax is payable on reverse charge.
16. Signature or digital signature of the supplier or authorised representative.

HSN and SAC digits

CGST + SGST or IGST?

• Intra-state supply (supplier and place of supply in the same state): CGST + SGST (or UTGST).
• Inter-state supply: IGST.

A wrong split is one of the most common invoice errors — and the customer can't simply "adjust" it later.

E-invoicing in brief

If your aggregate turnover crossed ₹5 crore in any financial year from 2017-18, B2B invoices, credit and debit notes and exports must be reported to the Invoice Registration Portal to get an IRN and QR code. Larger businesses also face time limits for reporting older invoices, so generate the IRN when you issue the invoice.

Time limits for issuing invoices

• Goods: before or at the time of removal or delivery.
• Services: generally within 30 days of supply (45 days for certain financial institutions).

Other documents you'll need

• Bill of supply — for exempt supplies or composition dealers (no tax charged).
• Credit note / debit note — to correct value or tax after an invoice is issued.
• Delivery challan — for movement of goods without a sale, such as job work.
• Receipt and refund vouchers — for advances.

A quick checklist before you send

• GSTINs and state codes correct on both sides.
• Invoice number unique for this financial year.
• HSN/SAC present with the right number of digits.
• Tax type (CGST+SGST vs IGST) matches the place of supply.
• Current GST rate for each item — rates were restructured from 22 September 2025, so re-check old item masters.
• Reverse charge shown where applicable.
• Signature or digital signature present.

Let software do the checking

MizUp Finance creates GST-compliant tax invoices, quotations, credit notes and delivery challans with the right tax split, HSN/SAC, place of supply and numbering series — and lets customers pay online. Start on the free plan, and read our tips on getting invoices paid faster.

Frequently asked questions