GST invoice format: what a tax invoice must show
Rule 46 of the CGST Rules lists what goes on a tax invoice. This generator lays them out in a standard GST bill format:
- Seller's name, address and GSTIN, and a consecutive invoice number (up to 16 characters, unique for the financial year) with the date.
- Buyer's name and address, and the buyer's GSTIN for a B2B sale.
- Place of supply with the state name and code, for inter-state sales.
- For each item: description, HSN or SAC code, quantity and unit, value, discount, taxable value, GST rate and the CGST, SGST or IGST amount.
- The total invoice value in figures and in words, and the signature of the supplier or an authorised person.
Tax invoice, bill of supply or plain bill?
A GST-registered seller issues a tax invoice for taxable sales. A composition dealer, or a seller of only exempt goods, issues a bill of supply, which shows no tax. A business without GST registration must not show or collect GST at all. This tool titles the bill “Tax Invoice” once you enter a valid GSTIN; leave the GSTIN blank and set the rates to 0% for a plain bill.
CGST + SGST or IGST on the bill
The tax type follows the place of supply. A shop in Coimbatore (33) billing a customer in Tamil Nadu charges CGST + SGST; the same bill delivered to a buyer in Karnataka (29) carries IGST. The generator reads the first two digits of both GSTINs, or the states you choose, and switches automatically. Not sure a GST number is right? Run it through the GSTIN checker.
Worked example
Gross ₹2,100 → discount ₹210 → ₹1,890 including tax → taxable value = 1,890 × 100 ÷ 105 = ₹1,800.00 → GST = 1,890 − 1,800 = ₹90.00 (CGST ₹45 + SGST ₹45) → total ₹1,890.
Before tax, ₹2,100 including 5% is a subtotal of ₹2,000 and a discount of ₹200, so the bill reads: subtotal ₹2,000 − discount ₹200 + GST ₹90 + round off ₹0 = ₹1,890. The same arithmetic check holds on every invoice this tool prints. To check one line by hand, use the GST calculator; for codes and rates, the HSN code finder.
B2B and B2C invoices
A B2B invoice goes to a GST-registered buyer: their GSTIN must be on it, because the buyer claims input tax credit from it and you report it invoice by invoice in GSTR-1. A B2C invoice goes to a consumer and needs no buyer GSTIN; small B2C sales are reported in GSTR-1 as state-wise totals. For an inter-state B2C sale above ₹1 lakh, also print the buyer's name, address and state. The same tax invoice format works for both — fill the buyer GSTIN only for B2B.
Common invoice mistakes to avoid
- Reusing or skipping invoice numbers — keep one series per financial year.
- Charging IGST to a buyer in your own state, or CGST + SGST across states.
- Old 12% or 28% rates after 22 September 2025.
- Missing HSN codes on B2B bills (4 digits up to ₹5 crore turnover, 6 above).
- A total that does not add up because each tax half was rounded on its own.