This notification mandates the number of HSN digits to be mentioned on tax invoices based on the aggregate turnover in the preceding financial year. Registered persons with turnover up to ₹1.5 crore are exempt, while those exceeding ₹1.5 crore and ₹5 crore are required to mention 2-digit and 4-digit HSN codes respectively. It is issued under rule 46 of the CGST Rules, 2017. The provision applies uniformly from the appointed date of GST.