GST invoice generator

How the tax split is decided

GST is one tax collected in two ways. When you and your customer are in the same state, the supply is intra-state and the tax is split down the middle: half goes to the centre as CGST and half to the state as SGST. An 18% invoice becomes 9% CGST plus 9% SGST. When the place of supply is a different state, the supply is inter-state and the whole 18% is charged as IGST, on one line.

The generator reads the state you selected and the place of supply, and switches between the two automatically. Change the place of supply and watch the totals block change with it.

Place of supply is usually the customer's location, but not always. For services tied to immovable property it is where the property sits; for events it is where the event happens; for goods that are not moved it is where they stand at the time of delivery. Sections 10 to 13 of the IGST Act carry the full list. If your work regularly touches those cases, confirm the treatment with your accountant rather than trusting a default.

What has to be on the invoice

Rule 46 of the CGST Rules sets out the particulars a tax invoice must carry. The layout above includes them: your name, address and GSTIN; a serial number unique within the financial year; the date; your customer's name, address and GSTIN where they are registered; the place of supply; a description of what you supplied; HSN or SAC codes; quantity and unit; taxable value; the rate and amount of tax; whether tax is payable on reverse charge; and a signature.

Two of those trip people up more than the rest. The serial number must be consecutive and unbroken within a financial year, which is why skipping a number to hide a cancelled invoice causes problems later. And the amount in words is expected on the document, which the generator produces for you in the Indian numbering system.

A note on privacy

Nothing you type here is transmitted anywhere. There is no server call in this page. If you tick the box to remember your business details, they are written to your own browser's local storage on this device and can be cleared with the button below the form or by clearing site data. Your customer's details are never stored, not even locally.

Common questions

Does this generator send my invoice data anywhere?

No. Every calculation runs in your browser and nothing is transmitted to a server. If you close the tab without printing or saving, the invoice is gone. Your business details are stored only in your own browser, and only if you tick the box to remember them.

How does it decide between CGST plus SGST and IGST?

It compares your state with the place of supply. When both are the same state, the tax is split into CGST and SGST at half the rate each. When they differ, the whole amount is charged as IGST. Exports, SEZ supplies and certain services under sections 12 and 13 of the IGST Act follow different rules, so check those with your accountant.

Is a printed invoice from this tool a valid tax invoice?

The layout carries the particulars listed in Rule 46 of the CGST Rules, including your GSTIN, a consecutive serial number, the place of supply, HSN or SAC codes, taxable value and the tax split. Validity also depends on the numbers you enter being correct and on your registration status, which only you and your accountant can confirm.

Do I need to put an HSN or SAC code on every line?

The number of digits required depends on your aggregate turnover in the previous financial year, and the requirement has been tightened over time. Enter the code your accountant uses for each item. The field is free text so you can enter four, six or eight digits as applicable to you.

Can I save an invoice and open it again later?

Not in this free tool, by design. It builds one invoice and forgets it. If you need a numbered history, saved customers and payment tracking, that is what the THQT app does.