CGST + SGST vs IGST — which one do you charge?
One rule decides it, and it has nothing to do with where you were sitting when you did the work. Here it is, with worked examples at 18% and the mistakes that cause return mismatches.
Last updated: 24 August 2026
Same state → CGST + SGST, at half the rate each.
Different state → IGST, at the full rate.
Same state means your place of business and the client's place of supply are in the same state.
At an 18% rate, side by side
| Situation | What you charge | Client pays |
|---|---|---|
| You in Andhra Pradesh Client in Andhra Pradesh |
CGST 9% + SGST 9% | 18% total |
| You in Andhra Pradesh Client in Karnataka |
IGST 18% | 18% total |
The total is identical. The client pays 18% either way. What changes is how that tax is split between the centre and the state, and how it appears in your GST returns. Nobody pays more or less because of this choice — which is exactly why people get careless about it.
Worked examples
Intra-state — you and the client both in Andhra Pradesh
Inter-state — you in Andhra Pradesh, client in Karnataka
Same ₹59,000 both times. Two tax lines in one case, one in the other.
What "place of supply" actually means
This is the part that trips people up, because the intuitive answer is wrong.
It is not where you are. Working from a cafe in Bengaluru for a week does not make your supplies inter-state or intra-state. Your registered place of business is what counts on your side.
On the client's side, the general position for services is:
- Client is GST-registered → place of supply is the location of that registered recipient. Their GSTIN tells you the state — the first two digits are the state code.
- Client is not registered → it generally follows the address on record with you, and where there is no such address, the supplier's location.
Several categories of service carry their own specific place-of-supply provisions, and exports of services are a separate matter entirely. If your work is anything other than a straightforward service billed to an Indian business, get it confirmed rather than assuming.
Let the invoice work it out
The free invoice generator switches between CGST/SGST and IGST the moment you pick the two states, and shows you which one it applied before you download. No signup, and nothing you type leaves your browser.
Open the free GST invoice generator →Reading the state from a GSTIN
A GSTIN starts with a two-digit state code. If your client's GSTIN begins with a different code than yours, it is an inter-state supply and IGST applies. For example, 37 is Andhra Pradesh and 29 is Karnataka — different codes, so IGST.
This is a quick sanity check, not a substitute for confirming the place of supply. A client can be registered in one state and the place of supply can still be somewhere else in specific situations.
Common mistakes
- Using the client's billing address instead of their GSTIN state. A head office address and the registered state are not always the same.
- Charging IGST because you travelled. Where you physically worked is irrelevant.
- Splitting IGST into two lines to make the invoice look consistent with older ones. Inter-state is one IGST line, full stop.
- Charging 9% + 9% but labelling both lines "GST". They must be identified as CGST and SGST separately.
- Treating a foreign client as inter-state. Export of services has its own treatment with LUT and zero rating. It is not IGST-as-usual.
If you got it wrong on an invoice already
The total tax collected is the same, but it sits under the wrong heads. That surfaces as a mismatch in your returns and can hold up your client's input tax credit — which is when they will call you about it.
It is correctable through the normal amendment route, but it means adjustments on both sides. Raise it with your chartered accountant rather than quietly switching the treatment on the next invoice and hoping the two cancel out.