CGST, SGST and IGST
One question decides it: does the supply stay inside your state, or leave it?
One question decides it: does the supply stay inside your state, or leave it?
Same state → CGST + SGST. Different state → IGST. And it is the place of supply that decides, not where you happen to be standing.
The tax splits in half. One half is CGST, which goes to the centre; the other is SGST, which goes to your state. So 18% becomes 9% + 9%, and 5% becomes 2.5% + 2.5%. The customer pays the same total either way — the split is about who receives it.
One line of IGST at the full rate. No split. 18% is one line of 18%.
For goods handed over the counter, it is where the goods are delivered. The customer's GSTIN begins with their state code — 27 is Maharashtra, 24 Gujarat, 07 Delhi — so a registered customer tells you themselves. For an unregistered customer it is the address you are supplying to.
This is why a wrong GSTIN is expensive: it can put the bill in the wrong table of your return and change the tax you charged. Our free GST number checker verifies the check digit, which is what catches a typo.
Charge CGST and SGST when it should have been IGST and your customer's input credit is in the wrong pot. Charge IGST when it should have split and the state gets nothing it was due. Both are corrected with a credit note and a fresh bill, which is work nobody wants.
Software should decide this from the customer's state rather than asking on a busy counter — that is what Aned Book does, and you can watch the same rule work in the GST calculator.
No. 18% is 18% either way. The difference is whether it arrives as one line or two, and who receives it.
The place of supply against your own state — not where you are sitting when you raise the bill.
The union territory equivalent of SGST. It behaves the same way in a bill: half the tax, alongside CGST.
Aned Book works the tax out from the bill you are raising, so none of the above is a decision anybody has to make at a busy counter.