HSN code

HSN stands for Harmonised System of Nomenclature, an international way of numbering goods. Under GST the HSN code is how you name what you sell: the code decides which rate applies, so two products that look similar can carry different rates because they fall under different codes.

Find your products' codes once, write them down, and use the same code every time. A wrong code means a wrong rate on the invoice, which your customer and the tax department will both notice.