Why does my bill show IGST instead of CGST + SGST?

Quick answerIn 3 steps

IGST is for a sale to another state; CGST + SGST for your own state. A website order delivered to another state is rightly IGST.
If a local bill shows IGST, check Settings → Business & GST → Address → State: it must match your GSTIN's first two digits.
For a branch, check that location's State: Settings → Shops & counters → Edit.

WhereSettings → Business & GST in the back office

Learn it properlyFill in Business & GST (legal name, trade name, GSTIN, State)Exactly as your GST certificate reads — it prints on every bill.Open the lesson →

Also asked as

“wrong GST type on a bill”
“inter-state tax on a local bill”