GST invoice format: every field your tax invoice must include

What a valid GST invoice must include

Under GST rules, these fields are mandatory on a tax invoice — miss one and it's not compliant, regardless of how the invoice looks.

• Invoice number & date A unique, sequential number for the financial year, plus the date of issue.
• Supplier details Your legal business name, address, and GSTIN.
• Recipient details Customer's name, address, and GSTIN if they're GST-registered.
• HSN/SAC code The applicable code for each good or service billed.
• Description, quantity & unit What was sold, how much of it, and the unit of measure.
• Taxable value The value of goods/services before tax, per line item.
• GST rate & amount CGST + SGST for sales within your state, or IGST for inter-state sales.
• Place of supply Required to determine whether CGST/SGST or IGST applies.
• Signature Of the supplier or an authorized representative (a scanned signature on a PDF is standard practice).

Frequently asked questions

• Is there one official GST invoice format? No — GST law specifies required fields, not a fixed visual template. Any invoice containing all the mandatory fields is valid.
• CGST, SGST, and IGST — what's the difference? Intra-state sales split GST into CGST + SGST. Inter-state sales charge the full amount as IGST instead.
• Do I need a GST invoice for every sale? If you're GST-registered, generally yes for taxable supplies — check the specific thresholds for your business with your CA.
• Can I generate GST invoices for free? Yes — your first 10 invoices and 10 estimates are free, no credit card required.