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Key takeaways
- A tax invoice is the document a registered supplier issues for a taxable supply. The buyer needs it to claim input tax credit.
- The invoice must carry a consecutive serial number of up to 16 characters, unique in the financial year.
- Goods: issue at or before removal. Services: within 30 days of supply, or 45 days for insurers, banks and financial institutions.
- E-invoicing applies from INR 5 crore turnover. Taxpayers at INR 10 crore and above must report an e-invoice within 30 days of its date from 1 April 2025.
Free PDF and Excel: GST tax invoice template and compliance checklist. Get it below
What a GST tax invoice is
A GST tax invoice is the document a registered supplier issues to a buyer for a taxable supply of goods or services, showing the tax charged. It is the basis on which the buyer claims input tax credit.
Rule 46 of the CGST Rules lists what the invoice must carry. Most queries from buyers' accounts teams come down to four things: the GSTIN, the place of supply, the HSN or SAC code and whether the tax split matches the movement of the goods.
A Bengaluru machine shop invoices a Chennai buyer for parts worth INR 1,00,000 taxable value. The goods move between states, so the invoice shows IGST, not CGST and SGST. The place of supply shows Tamil Nadu with its state code.
Had the shop shown CGST and SGST by mistake, the buyer's credit claim would be exposed to a mismatch and both sides would need to issue a correction.
Mandatory fields
| Field | What goes in it | Why it matters |
|---|---|---|
| Supplier name, address, GSTIN | Legal name as registered, full address and the 15-character GSTIN. | Buyer matches it to the portal record. |
| Invoice number | Consecutive serial number, up to 16 characters, unique per financial year. | Gaps and duplicates are audit flags. |
| Date of issue | The day of issue. | Starts the clock for the buyer's credit claim. |
| Recipient details | Name, address and GSTIN if registered. For an unregistered buyer, name, address and state. | Needed for reconciliation. |
| HSN or SAC code | Code for each item or service. | The digit length depends on turnover. Check the current notification. |
| Description, quantity, unit | What was supplied and how much. | Backs the taxable value. |
| Taxable value after discount | Value on which tax is charged. | Discounts must be shown, not netted silently. |
| Tax rate and amount | CGST and SGST, or IGST, and cess if any. | Must add up to the total. |
| Place of supply | State name and code for inter-state supplies. | Decides IGST versus CGST and SGST. |
| Reverse charge | Whether tax is payable on reverse charge, yes or no. | Moves the liability to the buyer. |
| Signature | Signature or digital signature of the supplier or representative. | E-invoices under the IT Act do not need one. |
Free PDF and Excel
GST tax invoice template and compliance checklist
A tax invoice layout with every rule 46 field, a tax-split worked example and a pre-issue checklist.
- Rule 46 invoice layout
- Field guide with reasons
- Pre-issue checklist
- Excel invoice that splits CGST, SGST and IGST
Try the tax split
Enter taxable value, the rate that applies to your HSN code and whether the supply stays inside one state. Confirm the rate on the government rate schedule.
Timing, e-invoice and when things change
| Item | Rule as at 19 October 2026 |
|---|---|
| Invoice for goods | Before or at the time of removal, or at delivery if goods do not move |
| Invoice for services | Within 30 days of supply, 45 days for insurers, banks, financial institutions and NBFCs |
| E-invoice required | Annual aggregate turnover of INR 5 crore or more |
| E-invoice reporting limit | 30 days from invoice date for turnover of INR 10 crore and above, from 1 April 2025 |
If you also move goods, read delivery challan for movements with no invoice and e-way bill for transport rules. For a sale where no tax is charged, see bill of supply.
Last checked: 19 October 2026. Fields and timing checked against published summaries of rule 46 and rule 47, and the GSTN advisory on the 30-day e-invoice reporting limit. Rates and HSN digit rules change by notification. Confirm with a chartered accountant.
Common errors
- Wrong GSTIN, even one digit off, which breaks the buyer's credit match.
- IGST and CGST mixed on one invoice.
- Missing place of supply on an inter-state sale.
- Invoice numbers restarted in the middle of the year.
- Late e-invoice reporting for large taxpayers, after which the portal will not accept it.
- GSTIN of both parties verified.
- Number is in sequence and within 16 characters.
- Place of supply and tax type match.
- HSN or SAC code on every line.
- Taxable value shown after discount.
- E-invoice generated if required, within the time limit.
Frequently asked questions
What is the difference between a tax invoice and a bill of supply?
A tax invoice charges GST. A bill of supply is used when no tax can be charged, such as by a composition taxpayer or for exempt supplies.
Is a signature required on a GST invoice?
Rule 46 asks for a signature or digital signature of the supplier. An e-invoice generated through the portal does not need one.
How long do I have to issue an invoice for services?
Generally 30 days from the date of supply. Insurers, banks and financial institutions including NBFCs get 45 days.
Who has to issue an e-invoice?
Businesses with annual aggregate turnover of INR 5 crore or more, subject to exemptions listed in the notifications.
Can I issue one invoice for several supplies?
Yes for one recipient, but each line needs its own HSN or SAC code and tax rate, and the invoice must remain within the rules on timing.