GST invoice format and requirements in India
A GST tax invoice in India must show the supplier's name, address and GSTIN, a unique serial number of up to 16 characters, the invoice date, the recipient's details and GSTIN if registered, the HSN or SAC code, a description and quantity, the taxable value, the GST rate and amount split into CGST and SGST or IGST, the place of supply for inter-State sales, whether reverse charge applies, and a signature.
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Mandatory fields on a GST tax invoice
Rule 46 of the CGST Rules, 2017 lists what a tax invoice must contain. These are the fields most service businesses and small sellers need, checked against the CBIC rules on 27 October 2026.
| Field | What to show |
|---|---|
| Supplier | Name, address and GSTIN |
| Invoice number | Consecutive serial number of up to 16 characters, unique for the financial year; letters, numbers, hyphens and slashes are allowed |
| Date | Date of issue |
| Recipient | Name, address and GSTIN or UIN if registered |
| Unregistered recipient, invoice of ₹50,000 or more | Name and address, delivery address, and the State name and code |
| HSN or SAC code | Code for the goods or service, with the required number of digits |
| Description and quantity | Description of goods or services, and quantity with unit for goods |
| Values | Total value, and taxable value after any discount or abatement |
| Tax | Rate and amount of CGST and SGST or UTGST, or IGST, and any cess |
| Place of supply | State name, for inter-State supplies |
| Delivery address | Where it differs from the place of supply |
| Reverse charge | Whether tax is payable on reverse charge |
| Signature | Signature or digital signature of the supplier or an authorised person |
CGST and SGST or IGST?
The tax split depends on whether the supply is within one State or between States. For an intra-State supply, where the supplier and the place of supply are in the same State, charge CGST and SGST at half the GST rate each; in a Union Territory without a legislature, UTGST replaces SGST. For an inter-State supply, charge the full rate as IGST. Show the place of supply on inter-State invoices so the customer can claim the right input tax credit.
Since 22 September 2025 most goods and services fall into the 5% or 18% GST rates, with 40% for a small group of luxury and sin goods. Professional and design services are usually 18%. Check the rate for your specific HSN or SAC code before invoicing.
HSN and SAC code digits
Goods use HSN codes and services use SAC codes. The number of digits depends on aggregate turnover in the previous financial year. Up to ₹5 crore, show at least 4 digits on B2B invoices; for invoices to unregistered customers, the code is optional at this turnover. Above ₹5 crore, show 6 digits on every tax invoice.
When to issue the invoice
- Services: within 30 days of supplying the service. Banks, insurers and some financial institutions have 45 days.
- Goods: before or at the time of removal for delivery, or of delivery to the recipient where no movement is involved.
- Small retail sales: a tax invoice need not be issued for a supply under ₹200 to an unregistered customer who does not ask for one, if a consolidated invoice is issued for such sales at the end of each day.
- Continuous supplies: on or before the due date of each payment or statement, where these are agreed in the contract.
E-invoicing: who must generate an IRN
Businesses whose aggregate turnover has exceeded ₹5 crore in any financial year since 2017-18 must issue B2B and export invoices as e-invoices. Each invoice is reported to an Invoice Registration Portal, which returns an Invoice Reference Number and a QR code to print on the invoice. Once a business crosses the threshold, the requirement continues even if turnover later falls.
From 1 April 2025, businesses with aggregate turnover of ₹10 crore or more must report each invoice, credit note and debit note within 30 days of its date; the portal rejects older documents. An invoice dated 1 April must be reported by 30 April. Below ₹10 crore, there is no 30-day limit at present. E-invoicing does not apply to B2C invoices, and some sectors such as banks and insurers are exempt.
Worked example: a design invoice from Bengaluru
Saffron Lines Studio is a fictional GST-registered design studio in Bengaluru, Karnataka, with turnover under ₹5 crore. It invoices a registered client for a brand identity project worth ₹50,000. The GST rate is 18%, and the SAC code is 998391 for specialty design services.
If the client is in Karnataka, the supply is intra-State: CGST at 9% is ₹4,500 and SGST at 9% is ₹4,500, for a total of ₹59,000. If the client is in Maharashtra, the supply is inter-State: IGST at 18% is ₹9,000, the total is still ₹59,000, and the invoice shows Maharashtra as the place of supply.
| Invoice line | Client in Karnataka | Client in Maharashtra |
|---|---|---|
| Taxable value | ₹50,000.00 | ₹50,000.00 |
| CGST 9% | ₹4,500.00 | Not charged |
| SGST 9% | ₹4,500.00 | Not charged |
| IGST 18% | Not charged | ₹9,000.00 |
| Invoice total | ₹59,000.00 | ₹59,000.00 |
| Place of supply | Karnataka | Maharashtra (27) |
Do you need GST registration?
Registration is generally required once aggregate turnover exceeds ₹20 lakh for service providers or ₹40 lakh for suppliers of goods only, with lower limits in some special category States. Inter-State suppliers of goods and some e-commerce sellers must register regardless of turnover. A business that is not registered must not charge GST or issue a tax invoice; it issues a bill of supply or ordinary invoice instead.
Credit notes, debit notes and corrections
Do not edit or reissue a tax invoice once it has been reported. If the value or tax falls after invoicing, for example because of a discount, return or deficient service, issue a credit note that refers to the original invoice. If the value or tax rises, issue a debit note. Both need the same supplier, recipient and tax details as an invoice.
Common GST invoice mistakes
- Charging CGST and SGST on an inter-State supply, or IGST on an intra-State one.
- Reusing an invoice number in the same financial year, or exceeding 16 characters.
- Leaving out the HSN or SAC code, or using too few digits for your turnover.
- Missing the place of supply on inter-State invoices.
- Missing an IRN and QR code when e-invoicing applies.
Keep invoices for six years
Under the CGST Act, accounts and records must be kept for 72 months, which is six years, from the due date for filing the annual return for the year they relate to. Store sales invoices, purchase invoices, credit notes and debit notes by month so they match your GST returns.
Common questions
What are the mandatory fields on a GST invoice in India?
The supplier's name, address and GSTIN, a unique serial number, the date, the recipient's details, the HSN or SAC code, description and quantity, taxable value, GST rate and amount, place of supply for inter-State sales, reverse charge status and a signature.
Should I charge CGST and SGST or IGST?
Charge CGST and SGST for a supply within the same State, and IGST for a supply between States. The total tax is the same; only the split differs.
How many HSN or SAC digits do I need on an invoice?
At least 4 digits if your previous-year aggregate turnover was up to ₹5 crore, and 6 digits above ₹5 crore. Up to ₹5 crore, invoices to unregistered customers do not need the code.
Who must use e-invoicing?
Businesses whose aggregate turnover has exceeded ₹5 crore in any financial year since 2017-18 must e-invoice B2B and export supplies. Those with turnover of ₹10 crore or more must report invoices within 30 days.
How long must GST invoices be kept?
For 72 months from the due date of the annual return for the year the records relate to.