GST Invoice Format: Mandatory Details and an Excel Template

A correct GST invoice format carries every detail listed in rule 46 of the CGST Rules: who is supplying to whom (with GSTINs), a unique invoice number and date, what was supplied (with HSN or SAC), the taxable value, the GST rate and amount, and the place of supply. Miss one and your customer may struggle to claim input tax credit.

Here is the full list, how to number invoices, when to charge CGST + SGST or IGST, the HSN and e-invoicing rules, and a worked example.

Details every tax invoice must show

• Supplier's name, address and GSTIN.
• A consecutive serial number, unique for the financial year, of up to 16 characters (letters, numbers, hyphen or slash).
• Date of issue.
• Recipient's name, address and GSTIN (if registered); for unregistered recipients with value over ₹50,000, the name, address and state.
• HSN code for goods or SAC for services.
• Description, quantity and unit of goods.
• Total value, and the taxable value after discounts.
• GST rate and amount, split into CGST and SGST/UTGST, or IGST, plus any cess.
• Place of supply with the state name, for inter-state supplies.
• Delivery address, if different from the place of supply.
• Whether tax is payable under reverse charge.
• Signature or digital signature of the supplier or an authorised person.

Invoice numbering

Numbers must run in sequence within the financial year and never repeat. A simple pattern such as RPC/26-27/0001 fits within 16 characters and restarts each April. You may run separate series – for example one per branch or one for exports – as long as each is consecutive and declared in your GSTR-1 document summary.

CGST + SGST or IGST?

Compare the supplier's state with the place of supply. If they're the same, charge CGST and SGST (half the rate each). If they differ, charge IGST at the full rate. For goods, the place of supply is usually where delivery ends; for most services to a registered business, it's the recipient's location.

Since 22 September 2025, most goods and services fall into the 5% or 18% slabs, with a 40% rate for a short list of luxury and sin goods. Check the rate for each HSN before you invoice; the GST calculator helps with inclusive and exclusive amounts.

HSN codes and e-invoicing

• HSN digits: businesses with turnover up to ₹5 crore show 4-digit HSN on B2B invoices; above ₹5 crore, 6 digits on all invoices.
• E-invoicing: businesses with turnover above ₹5 crore must generate an IRN on the invoice registration portal for B2B invoices; the invoice then carries the IRN and QR code.
• Bill of supply: composition dealers and suppliers of exempt goods issue a bill of supply instead of a tax invoice, without GST.

Worked example

A Raipur manufacturer sells 40 brass bushes at ₹350 each to a buyer in Nagpur, with a 5% trade discount, at 18% GST.

1. Value: 40 × ₹350 = ₹14,000; less 5% discount ₹700 = taxable value ₹13,300.
2. Place of supply is Maharashtra and the supplier is in Chhattisgarh, so charge IGST.
3. IGST at 18%: ₹2,394. Invoice total: ₹15,694.
4. Show HSN, quantity with the unit (NOS), place of supply "27 – Maharashtra", reverse charge "No", and the amount in words.

Keeping invoices and the sales register together

The invoice is half the job. Every invoice also needs to flow into your sales register and GSTR-1 – B2B by GSTIN, B2C large and small, HSN summary and document summary. Our free GST Invoice Format & Sales Register template prints a rule 46 invoice with the amount in words and builds the register and HSN summary from the same data. The Pro edition adds a GSTR-1 summary, credit and debit notes, and payment tracking.

Freelancers billing services can use the simpler Freelancer Invoice & Payment Tracker, which also tracks TDS deducted by clients.