Put in what the buyer paid and see the tax, split the way an invoice splits it — CGST and SGST when the goods stay in your state, IGST when they cross a state line. Nothing to sign up for.
GST rate
Which rate applies is an HSN question. Your CA or your HSN code decides it — this does not guess.
Same state, so this is CGST plus SGST — half each, both to the same place.
CGST and SGST add back to the GST above. Any odd paise sits in SGST, which is what an invoice does.
This works out the tax on one sale. It is not tax advice, and it does not know your registration — your CA does. Inside OMS Pro the same arithmetic runs on every order you ship, and produces the GSTR-1 file per registration.
Where the goods go decides it, not where they were listed. Goods staying inside the state you are registered in are CGST plus SGST, half each. Goods crossing into another state are IGST, in one line. Getting it the wrong way round pays money to the wrong government, and that is the mistake that takes a CA to unpick.
On a marketplace it almost always is — what the buyer paid has the tax in it. Treating that figure as the value before tax reports more tax than you owe and a bigger sale than you made, on every line, all month. Switch the calculator above to work backwards from the price instead.
This same arithmetic runs on every order inside OMS Pro — on the invoice, and again in the month's GSTR-1, produced one GSTIN at a time in the file the portal reads.
