ET Explainer: What’s in a number? A lot when it is numerical code HSN by: avneetgrover 2 years ago Trade & Finance No Comments In India, declaring a 4-digit HSN code is mandatory on goods and services tax (GST) invoices by businesses with turnover up to Rs 5 crore and a 6-digit code on invoices by businesses with a turnover of more than Rs 5 crore Share: avneetgrover