It decides the tax split for you
A GST invoice shows CGST and SGST when the supplier and the place of supply are in the same state, and a single IGST column when they are not. That is not a matter of opinion once both states are known, so this tool works it out rather than asking you to choose.
The place of supply is seeded from your customer's GSTIN and you can change it. It is not always the customer's own state — it follows where the supply actually happens — so if you change it, the tool takes your word for it and only mentions the difference.
You set the rate on each line. The tool never picks one for you, and it does not carry a table of rates by HSN or SAC code. Rates move, and a stale number printed on your invoice is your compliance problem, not ours. Confirm the rate with your accountant.
Your GSTIN is checked as you type
A GSTIN is fifteen characters: two digits for the state, ten for the PAN, one for the entity, a letter Z, and a final check character calculated from the other fourteen.
As you type, the tool shows how many characters are in, names the state as soon as the first two digits land, and verifies the check character once all fifteen are present. If the check character looks wrong it says which one it expected.
It never stops you. You may be copying a customer's GSTIN from their purchase order, and if that number is wrong you still need to raise the invoice. The tool tells you what it sees and leaves the decision with you.
HSN and SAC codes
Each line takes its own HSN or SAC code, and the codes you enter are grouped into the tax summary block that a GST invoice is expected to carry.
A short list of common service codes is offered as suggestions, with their official descriptions and no rates attached. Which code applies to what you sell is a question for your accountant, not for a web form.
For hotels
There is a hotel example that fills in the shape of an accommodation bill — a room tariff line under SAC 996311 and a restaurant line under 996331, with units and quantities. It leaves the rate and the tax percentage blank for you to fill in.
That blank is deliberate. Accommodation slabs changed in September 2025, and a tool that quietly prefills last year's percentage is worse than one that asks. If you run a property and want this raised automatically from the stay itself, that is what our PMS does.