GST Invoice Format: The Complete Checklist (Rule 46)
Written by Naresh, Founder of QWIK INVOICE · Last updated: 15 August 2026
A compliant GST tax invoice needs 13 things, set out in Rule 46 of the CGST Rules, 2017. Miss one and the invoice is technically non-compliant — which can block your customer from claiming input tax credit on it. Below is the complete checklist as a single reference table, with links to the guides that cover the trickier fields (numbering, HSN/SAC, the CGST/SGST/IGST split) in full depth.
What fields does a GST invoice legally need?
Every field below comes from Rule 46. Some fields have their own detailed rules — where that's the case, this checklist states the requirement plainly and links out to the guide that covers it properly, rather than repeating it.
| # | Field | Requirement | Notes |
|---|---|---|---|
| 1 | Supplier details | Name, address, GSTIN | Your registered business details |
| 2 | Invoice number | Consecutive, unique for the financial year, max 16 characters | See the numbering guide for the full rule |
| 3 | Date of issue | The date the invoice is issued | — |
| 4 | Recipient details | Name, address, GSTIN if registered | If unregistered and invoice value ≥ ₹50,000: name, address and state still required |
| 5 | HSN/SAC code | Minimum digit count depends on turnover | See the HSN/SAC guide |
| 6 | Description | Description of goods or services | — |
| 7 | Quantity & unit | For goods: quantity and unit of measurement | Not applicable in the same sense for services |
| 8 | Taxable value | Value after any discount, before tax | — |
| 9 | GST rate | The applicable rate(s) | — |
| 10 | Tax amount | CGST/SGST or IGST, as applicable | See the CGST/SGST/IGST guide |
| 11 | Place of supply | Mandatory for inter-state supplies | — |
| 12 | Reverse charge | Whether tax is payable on reverse charge | See the reverse charge guide |
| 13 | Signature | Supplier's or an authorized representative's signature | Digital signature accepted; electronic-invoice exemptions exist — confirm on the GST portal |
Which fields change if the sale isn't straightforward?
Two fields on this checklist point somewhere else deliberately, because they're rules in their own right, not just a blank to fill in. The tax-amount field depends entirely on whether the sale is intra-state or inter-state — see CGST vs SGST vs IGST Explained for the full decision rule and worked examples. And if the sale doesn't attract GST at all — an exempt sale, or you're registered under the composition scheme — you don't issue a tax invoice at all; see GST Invoice vs Bill of Supply for when to use each document.
How many copies of an invoice should I keep?
For goods, the standard convention is three copies: original (marked for the recipient), duplicate (marked for the transporter), and triplicate (kept by the supplier). For services — where no transporter is involved — two copies is typical: original for the recipient, duplicate retained by the supplier. This isn't a strict Rule 46 field requirement so much as standard practice reflecting who actually needs a physical/reference copy; a digital tool that lets you re-download or reprint a saved invoice at any time effectively satisfies the same need.
What does a compliant invoice actually look like, field by field?
Picture a freelance web designer in Maharashtra invoicing a Maharashtra-based client for a ₹25,000 website project. The invoice header shows the designer's business name, address and GSTIN. Below it: an invoice number like INV-0042, the date, and the client's name, address and GSTIN. The line item reads "Website design and development," SAC code, quantity 1, taxable value ₹25,000. Below that: GST rate, CGST ₹2,250 + SGST ₹2,250 (same state — see the tax-split guide), place of supply, and a grand total of ₹29,500. A signature block sits at the bottom. Every one of those pieces maps directly to a row in the checklist table above — which is exactly what QWIK INVOICE's invoice generator assembles automatically from the details you enter once in Settings.
Common checklist mistakes worth double-checking
- Leaving the place of supply blank on an inter-state invoice — it's mandatory there, not optional.
- Showing a GSTIN field but leaving it visibly empty for a registered B2B customer, instead of actually capturing it.
- Reusing an old invoice's number by mistake, breaking the "consecutive, unique per financial year" rule — see the numbering guide for how to avoid this.
- Applying a tax split (CGST+SGST) when the sale should have used IGST, or vice versa — see the tax-split guide's worked examples before you invoice a new-state customer for the first time.
Frequently asked questions
Is a signature mandatory on every GST invoice?
Yes, in principle — a tax invoice must carry the signature or digital signature of the supplier or an authorized representative. There are specific exemptions for invoices issued in electronic form in a manner prescribed by the CBIC, so if you're generating invoices purely digitally, confirm the current signature requirement on the GST portal or with a tax professional rather than assuming it doesn't apply.
What happens if I forget a mandatory field on an invoice?
A tax invoice missing a mandatory Rule 46 field is technically non-compliant, which can cause problems for your customer claiming input tax credit on it and can be flagged in a GST audit. It's usually correctable — either by reissuing the invoice correctly (if not yet reported) or via a credit/debit note process — but it's much easier to get the checklist right the first time. A tool like QWIK INVOICE fills most mandatory fields automatically.
Do I need the recipient's GSTIN on every invoice?
You need it whenever the recipient is GST-registered (a B2B sale). For an unregistered customer (B2C), you don't have a GSTIN to show — but if the invoice value is ₹50,000 or more, you generally still need the recipient's name, address and the state, even without a GSTIN.
How many copies of an invoice do I actually need to keep?
For goods, the standard practice is three copies — original (for the recipient), duplicate (for the transporter), and triplicate (for the supplier's own records). For services, since there's no transporter involved, two copies are typical — original for the recipient and duplicate for the supplier. Digital invoicing tools like QWIK INVOICE let you regenerate/reprint a saved invoice at any time, which covers this in practice.
Is there one official GST invoice format prescribed by the government?
No. Rule 46 of the CGST Rules lists the particulars a tax invoice must contain but does not prescribe a layout, so any design that carries every required field is valid. The exceptions are e-invoices, which follow the format the e-invoice system generates, and B2C invoices covered by the dynamic QR code rule.
Does a GST invoice need place of supply and reverse charge fields?
Yes. The invoice must show the place of supply, with the state name, when the supply is inter-state, and it must state whether tax is payable on reverse charge. Both are on the Rule 46 list. If your template or generator has no separate field for them, add them as a line in the notes or footer rather than leaving them out.
What are the mandatory fields in a GST tax invoice format?
Supplier name, address and GSTIN; a consecutive invoice number of up to 16 characters; the date of issue; recipient details, with GSTIN if registered; HSN or SAC code; description of goods or services; quantity and unit for goods; taxable value after discount; GST rate and the tax amount split into CGST and SGST or IGST; place of supply for inter-state sales; whether tax is payable on reverse charge; and a signature or digital signature. The table above walks through each one.
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