HSN code
What HSN code means, where you will meet it and what it means for your business.
DefinitionAn HSN code is the Harmonised System of Nomenclature number that classifies goods for GST, printed on every invoice: 4 digits for turnover up to ₹5 crore and 6 digits above.
The HSN is a global product classification of about 5,000 headings that India adopted for GST. Each code maps to a tax rate, so choosing the right one decides whether you charge 5%, 18% or 40%. Businesses with aggregate turnover up to ₹5 crore must quote at least 4 digits on B2B invoices (optional on B2C), and businesses above ₹5 crore quote 6 digits on all invoices; exporters use 8 digits. You meet HSN codes when setting up products in billing software, in GSTR-1's HSN summary table, and on e-way bills. What it means for you: a wrong code can mean short payment and a demand with interest, or overcharging that loses you customers. Rate changes, such as the September 2025 rationalisation, are announced by HSN, so keep your product master current.