You never have to choose the type of GST yourself. We work it out from your details and your client's.
The basic rule
We compare your state (from your GSTIN) with the place of supply: your client's state, taken from their GSTIN or, if they have none, the state on their address.
| Situation | GST charged |
|---|---|
| Client in the same state | CGST + SGST, half the rate each (18% = 9% + 9%) |
| Client in a different state | IGST at the full rate |
| Same union territory without a legislature (e.g. Chandigarh) | CGST + UTGST |
Special cases
- Client outside India: an export of services, which is zero-rated. If you have a Letter of Undertaking (LUT), no GST is charged and the invoice says so. Otherwise IGST is charged and you claim a refund.
- SEZ client: zero-rated, in the same way as exports.
- Composition scheme (you): you issue a Bill of Supply with no GST.
- Not registered for GST (you): your invoices show no GST.
- Reverse charge: for notified services the client pays the GST. The invoice shows it but doesn't add it to the total.
Rates
Rates are stored with the date they start, so a rate change applies automatically from its effective date. Since 22 September 2025 the main GST rates are 5%, 18% and 40% (plus 0%, 0.25% and 3% for specific goods).
These rules follow the GST law as we understand it. Your accountant should still check your first few invoices.