HSN code disclosure: turnover-based digit reporting in tax invoices mandated from July first, 2017 for registered taxpayers. Registered persons must state the digits of the Harmonised System of Nomenclature (HSN) Codes in tax invoices according to turnover-based thresholds: no HSN digits for the lowest turnover band, two digits for the middle band, and four digits for the highest band, as prescribed in the notification; the requirement is effective from the commencement date set in the notification and applies under the first proviso to rule 46 of the Assam GST Rules, 2017.