What Is a GST Invoice?
A GST invoice is the bill a GST-registered business issues when it supplies goods or services. It records what was sold, to whom, at what value and how much GST was charged. Your buyer needs a correct GST invoice to claim input tax credit, and you need it to file your returns. A wrong or incomplete invoice can delay both.
Mandatory Fields in a GST Invoice Format (Rule 46)
| # | Field | Notes |
|---|---|---|
| 1 | Supplier name, address and GSTIN | Your registered details |
| 2 | Invoice number | Unique for the financial year, up to 16 characters; letters, numbers, hyphen (-) and slash (/) allowed |
| 3 | Invoice date | Date of issue |
| 4 | Recipient name, address and GSTIN | GSTIN if the buyer is registered |
| 5 | Unregistered buyer details | Name, address, delivery address, state name and code when taxable value is ₹50,000 or more |
| 6 | HSN or SAC code | Digits required depend on your turnover |
| 7 | Description of goods or services | |
| 8 | Quantity and unit | For goods |
| 9 | Total value | |
| 10 | Taxable value | After discount or abatement |
| 11 | GST rate | CGST + SGST/UTGST for intra-state, IGST for inter-state, plus cess if any |
| 12 | GST amount | Tax charged for each rate |
| 13 | Place of supply | With state name, for inter-state supplies |
| 14 | Delivery address | If different from place of supply |
| 15 | Reverse charge | Whether tax is payable on reverse charge |
| 16 | Signature | Signature or digital signature of supplier or authorised person |
| 17 | QR code with IRN | Only for businesses under e-invoicing |
Sample GST Invoice Format
| Field | Example |
|---|---|
| Supplier | Shree Packaging Pvt Ltd, MIDC Chakan, Pune, Maharashtra · GSTIN 27XXXXX1234X1ZX |
| Invoice no. / date | SP/25-26/0142 · 14 Oct 2025 |
| Buyer | Om Auto Parts, Bhosari, Pune, Maharashtra · GSTIN 27XXXXX5678X1ZX |
| Place of supply | Maharashtra (27) |
| Item | Corrugated boxes 5-ply · HSN 4819 · 1,000 nos × ₹125 |
| Taxable value | ₹1,25,000 |
| CGST 9% | ₹11,250 |
| SGST 9% | ₹11,250 |
| Invoice total | ₹1,47,500 |
| Reverse charge | No |
Sample figures for illustration only. GSTINs are masked.
Because supplier and buyer are both in Maharashtra, this is an intra-state supply, so tax is split into CGST and SGST. If the buyer were in Karnataka, the same ₹22,500 would be charged as IGST at 18%.
Types of GST Invoice Format
| Document | When to use it |
|---|---|
| Tax invoice | Registered business sells taxable goods or services |
| Bill of supply | Supply is exempt, or the seller is under the composition scheme |
| Export invoice | Goods or services exported; shows "supply meant for export" with or without IGST payment |
| Credit note | Reduce value or tax on an earlier invoice, for example after a return |
| Debit note | Increase value or tax on an earlier invoice |
| Receipt voucher | Advance received before supply |
HSN Code Digits on a GST Invoice
| Annual aggregate turnover (previous year) | HSN digits required |
|---|---|
| Up to ₹5 crore | 4 digits on B2B invoices |
| Above ₹5 crore | 6 digits on all invoices |
E-Invoice: When Your GST Invoice Format Changes
Businesses whose aggregate turnover has exceeded ₹5 crore in any financial year since 2017-18 must generate e-invoices. The invoice is uploaded to the Invoice Registration Portal (IRP), which returns an Invoice Reference Number (IRN) and a QR code that must be printed on the invoice. Businesses with turnover of ₹10 crore or more must report invoices to the IRP within 30 days of the invoice date.
How Many Copies of a GST Invoice?
- Goods: three copies. Original for the buyer, duplicate for the transporter, triplicate for the supplier.
- Services: two copies. Original for the buyer, duplicate for the supplier.
Common GST Invoice Mistakes
- Wrong place of supply. Charging CGST and SGST when IGST applies, or the reverse.
- Missing buyer GSTIN on a B2B invoice, so the buyer can't claim input tax credit.
- Broken invoice series. Duplicate or skipped numbers within the financial year.
- Wrong HSN digits for your turnover band.
- No signature on a printed invoice.
Free GST Invoice Format Template
Download a ready GST invoice format with every mandatory field.
Want to see what is inside first? Open the GST invoice template page.
Skip the Template: Make GST Invoices in Mera Udyog
A template works for a few invoices a week. Once you’re billing from more than one plant or outlet, you need invoices that pull customer details automatically and show who has paid. Mera Udyog’s GST billing software does both.
This page is general guidance, not tax advice. Check specific cases with your CA.