What an HSN code is
HSN stands for Harmonised System of Nomenclature. It's a numbering system that classifies goods for tax. Every product you sell has an HSN code, and that code decides its GST rate. Get the code right and the correct tax follows on its own. Get it wrong and every invoice for that product is off.
Why it matters for your GST
The HSN code is the link between your product and its tax slab. It's mandatory on your invoices and in your GST returns. Tax officers use it to check you've charged the right rate. It's not paperwork for its own sake. It's how the system knows a shirt is taxed differently from a laptop.
How many digits you need
The number of HSN digits you must show depends on your turnover. Smaller sellers show fewer digits; larger ones show more, usually up to six or eight. More digits means a more specific classification. Check the current requirement for your turnover band, and use at least that many on every invoice.
How to find your code
Start with the official GST HSN lookup, or a reliable rate finder. Search by the product name and read the description carefully — similar products can sit under different codes. When two codes look close, the exact wording of the description decides. If a product is unusual, confirm with a CA rather than guess.
Common mistakes to avoid
Sellers slip up in predictable ways. Using one code for a whole mixed catalogue. Copying a competitor's code without checking. Picking the code with the lowest rate instead of the correct one. Each of these invites a mismatch that surfaces at filing time, when it's hardest to fix.
Set it once, per product
The clean way is to store the right HSN code against each product when you add it. Then every invoice and every return pulls the correct code and rate on its own. You do the classification work once, up front, instead of on every single order for the rest of the year.
Where your store helps
The Storemate keeps the HSN code with each product, so the right code and GST slab flow onto every invoice automatically. Set it when you add the product, and the tax math takes care of itself. This is a starting point, not tax advice — confirm unusual classifications with a professional.