A GST tax invoice is the document that lets your customer claim input tax credit and lets you prove the tax you collected. The law does not prescribe one fixed design, but it does list the particulars that must be on it. This guide walks through them in plain language.
What is a GST tax invoice?
A registered supplier issues a tax invoice for a taxable supply of goods or services under Section 31 of the CGST Act, 2017. The particulars are listed in Rule 46 of the CGST Rules, 2017. If you are a composition dealer or you supply only exempt goods or services, you issue a bill of supply instead, and you do not collect GST.
Mandatory particulars on a tax invoice
- Your name, address and GSTIN.
- A consecutive serial number, not more than 16 characters, unique for the financial year.
- The date of issue.
- The buyer's name, address and GSTIN (if the buyer is registered).
- For an unregistered buyer: name, address and delivery address with state name and state code when the taxable value is ₹50,000 or more, or when the buyer asks for it to be recorded.
- HSN code for goods or accounting code (SAC) for services.
- Description of the goods or services, and for goods the quantity and unit.
- Total value, the discount, and the taxable value after discount.
- Rate and amount of tax: CGST, SGST (or UTGST), IGST and cess where applicable.
- Place of supply with the state name, in case of an inter-state supply.
- Delivery address, where it is different from the place of supply.
- Whether tax is payable on reverse charge.
- Your signature or digital signature, or that of your authorised representative.
Rules change from time to time. Treat this list as a checklist and confirm against the current CGST Rules on the CBIC website or with your CA.
Invoice numbering rules
The invoice number must be consecutive and unique for the financial year, up to 16 characters, and can use letters, digits, a hyphen and a slash. Many businesses put the financial year in the series so numbers restart every April, for example INV-26-27/0001.
You may keep separate series for separate branches or document types, as long as each series is consecutive and the combination never repeats within the year. In Rashtra Bill you set the invoice prefix once in Settings and the next number is generated for you.
When must the invoice be issued?
- Goods: at or before the time the goods are removed or delivered to the buyer.
- Services: within 30 days of supplying the service (45 days for insurers, banks and other financial institutions, including NBFCs).
Number of copies
For goods, the invoice is prepared in three copies: original for the recipient, duplicate for the transporter and triplicate for the supplier. For services, two copies: original for the recipient and duplicate for the supplier. A PDF sent electronically serves as your copy of record.
A sample layout
| Section | What goes there |
|---|---|
| Header | Business name, address, GSTIN, logo, the words TAX INVOICE |
| Invoice details | Invoice number, date, due date, place of supply with state code, reverse charge Yes/No |
| Buyer | Billed-to name, address, GSTIN; ship-to address if different |
| Item table | Serial no., description, HSN/SAC, quantity, unit, rate, discount, taxable value, GST rate, tax amount |
| Totals | Taxable value, CGST + SGST or IGST, round-off, grand total, amount in words |
| Footer | Bank and UPI details, terms, signature, "computer generated" or authorised signatory |
Making this automatic
With Rashtra Bill you enter your GSTIN, address, bank and signature once. When you create an invoice, the place of supply and tax type are worked out from the two states, each item brings its HSN/SAC and GST rate, the total is converted to words, and the PDF is ready to download or print. You can try it on the free plan.
Frequently asked questions
Is it compulsory to show HSN code on a GST invoice?
Yes for most registered businesses, but the number of digits depends on your aggregate turnover in the previous financial year. Check the current notification or ask your CA which applies to you. See our guide on HSN and SAC codes.
Can I issue an invoice without the buyer's GSTIN?
Yes, when the buyer is not registered (a B2C sale). In that case other details such as address and state apply instead, as listed above.
What is the difference between a tax invoice and a bill of supply?
A tax invoice shows GST charged and is issued by registered taxpayers for taxable supplies. A bill of supply has no tax and is issued by composition dealers or for exempt supplies.
This guide is general information for small businesses, not legal or tax advice. GST rules, rates and thresholds are changed by notification, so check the current position on the GST portal or with your chartered accountant before acting.