GST invoice format and free GST invoice generator

A GST invoice isn't just a bill. For a registered business, the CGST Rules set out what it must show — your GSTIN, the buyer's details, HSN or SAC codes, the place of supply and the tax split — so your buyer can claim input tax credit and your GSTR-1 lines up.

This page walks through the GST invoice format field by field, shows how CGST, SGST and IGST are worked out, and links to a free GST invoice generator that does the split for you. There's no sign-up: as a guest, your invoice stays in your browser until you download the PDF.

Tax invoice, bill of supply or plain invoice?

The title on your invoice depends on how you are registered under GST:

You are	Document title	Charges GST
Regular GST-registered seller	Tax Invoice	Yes
Composition dealer	Bill of Supply	No
Not registered under GST	Invoice	No

A composition dealer's bill of supply must also say "Composition taxable person, not eligible to collect tax on supplies". An unregistered freelancer or small business should never title a document "Tax Invoice" or show GST on it. In Invoice Native you pick your registration type and the title and wording follow.

What to include on a GST tax invoice

• Title — "Tax Invoice" (or "Bill of Supply" / "Invoice", as above).
• Invoice number of at most 16 characters, using only letters, digits, - and /, unique within the financial year (April–March). A series such as INV/26-27/0001 works well.
• Invoice date in DD/MM/YYYY.
• Your legal name, address, GSTIN, and state with its code, for example "Maharashtra (27)".
• Buyer's name, billing address and state. Add the buyer's GSTIN when they are registered (B2B). For an unregistered buyer, name, address and state are required when the value is ₹50,000 or more.
• Place of supply — the state name and code, or "Outside India" for exports.
• Delivery address if it differs from the billing address.
• Each line: description, HSN (goods) or SAC (services) code, quantity and unit, rate, discount, taxable value and GST rate.
• Tax summary per rate: taxable value and CGST + SGST (or UTGST), or IGST, with rate and amount.
• Total, round off and amount in words, such as "Indian Rupees Eleven Thousand Eight Hundred Only".
• "Tax is payable on reverse charge: Yes/No".
• Authorised signatory block.

Worked example: CGST + SGST vs IGST

Say you are a designer in Maharashtra and bill ₹10,000 for services at 18% GST. The tax depends on where the supply is made.

Line	Intra-state (buyer in Maharashtra)	Inter-state (buyer in Karnataka)
Taxable value	₹10,000.00	₹10,000.00
CGST @ 9%	₹900.00	—
SGST @ 9%	₹900.00	—
IGST @ 18%	—	₹1,800.00
Total	₹11,800.00	₹11,800.00

The buyer pays the same total either way; what changes is which government collects the tax. If the seller's state is a union territory without a legislature (such as Chandigarh or Ladakh), the intra-state split is CGST + UTGST instead of CGST + SGST.

Round off works on the final total. On a taxable value of ₹4,237 at 18%, CGST and SGST are ₹381.33 each, so the total is ₹4,999.66. A round-off row of +₹0.34 brings the amount due to ₹5,000.00.

Place of supply: the field that decides the tax

Place of supply is usually the buyer's state for services to a registered buyer, and it is what decides between CGST + SGST and IGST. In the generator it defaults to the buyer's state — pre-filled from the buyer's GSTIN when you enter one — and you can change it when the rules for your supply point elsewhere. Place-of-supply rules have many special cases (events, property, transport, goods delivered elsewhere), so if yours is unusual, check with a chartered accountant.

HSN and SAC codes

HSN codes classify goods and SAC codes classify services (SAC codes are 6 digits and start with 99). With turnover up to ₹5 crore, at least 4 digits are generally needed on B2B lines and the code is optional on B2C lines; above ₹5 crore, 6 digits are needed on every line. Look up the right code and rate for each item — Invoice Native checks the format, not whether the code or rate fits your product.

GST rates on the invoice

Each line carries its own rate, so one invoice can mix, say, 5% and 18% items; the tax summary shows each rate separately. The editor offers the current slabs (0%, 0.25%, 3%, 5%, 18% and 40%) plus the older 12% and 28%, and you can type any other rate.

Exports and SEZ supplies

For an export or a supply to an SEZ, set the supply type. Under a letter of undertaking (LUT) or bond, the supply is zero-rated: no IGST is charged, the invoice carries the export endorsement, and you can print your LUT reference. With payment of IGST, the full rate is charged as IGST. Place of supply for exports is "Outside India".

Common mistakes on GST invoices

• Charging IGST on an intra-state sale, or CGST + SGST on an inter-state one, because place of supply was not checked.
• "Tax Invoice" on a composition dealer's or unregistered seller's document.
• Invoice numbers longer than 16 characters, or a series that repeats within the financial year.
• Missing buyer GSTIN on a B2B invoice, which can cost your buyer their input tax credit.
• No amount in words or no reverse-charge statement.
• Guessing HSN/SAC codes or rates instead of checking them.

Checklist

• ✅ Right title for your registration type
• ✅ Invoice number of 16 characters or fewer, unique in the financial year
• ✅ Your GSTIN and state code; buyer's GSTIN for B2B
• ✅ Place of supply with state name and code
• ✅ HSN/SAC, rate and taxable value on every line
• ✅ CGST + SGST (or UTGST) or IGST, matching the place of supply
• ✅ Total, round off and amount in words
• ✅ Reverse charge Yes/No and authorised signatory

Taking an advance or cash payment instead of billing? See our money receipt format.