Free GST, tax & invoice tools

Generate invoices, validate GSTINs, find HSN codes, and run GST, TDS & income-tax numbers — accurate, instant, no sign-up. The same engines that power OnGravy's books, built for Indian business owners and their CAs.

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GST Invoice Generator

Make a GST tax invoice with the CGST/SGST/IGST split done for you — download the PDF.

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Income Tax Calculator

Old vs new regime, FY 2026-27 — see which saves you more.

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HSN Code Finder

Search any product or service → its HSN/SAC code and GST rate.

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GST Rates by Product

Browse GST rates for common goods & services, 0% to 28%.

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GSTIN Validator

Validate a GST number, decode the state, PAN and entity type.

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GST Calculator

Add or remove GST, with the CGST/SGST/IGST split done for you.

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TDS Rate Finder

Rate + amount for 194C, 194J, 194I, 194H and more.

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GST Late Fee Calculator

Late fee + 18% interest on a delayed GSTR-3B / GSTR-1.

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Advance Tax Calculator

Installment schedule + §234B/234C interest estimate.

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GST Registration Checker

Do you need GST registration, e-invoicing, or composition?

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Stop calculating. Let your books do it.

OnGravy runs GST, TDS and income tax on your real transactions automatically — and prepares the returns your CA can file.

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