Guide · India GST
How to add GST to an invoice in India
A practical checklist for freelancers and small businesses: what to show on an invoice, how to split CGST/SGST or IGST, and how to check your math with Decodexo’s free GST calculator.
1. Start with the taxable value
The taxable value is the price before GST. If you quote ₹10,000 for a service and GST is extra, ₹10,000 is taxable. If your quote already includes GST, use Remove GST in the calculator to find the taxable portion.
2. Pick the correct GST rate
Common slabs are 5%, 12%, 18%, and 28%. Many B2B services use 18%. Confirm the rate for your HSN/SAC with your CA or the GST rate schedule — this guide does not replace professional advice.
3. Intra-state vs inter-state
- Same state (supplier and buyer): show CGST and SGST, each half of the total GST.
- Different states: show IGST (full GST amount).
4. Worked example (18% GST, intra-state)
Taxable value ₹5,000 → GST ₹900 (18%) → CGST ₹450 + SGST ₹450 → Invoice total ₹5,900.
5. Put it on the invoice
Include GSTIN (if registered), invoice number, date, line items, taxable value, GST breakup, and total. You can draft a PDF using the invoice generator, then merge or compress PDFs if needed.