Conditional interest relief under GST extends filing deadlines for delayed GSTR-3B returns across turnover-based taxpayer classes. Conditional reduction of interest liability was provided for registered persons who failed to furnish FORM GSTR-3B and pay tax by the due date for February 2020, March 2020 and April 2020. The concession depended on aggregate turnover in the preceding financial year and on furnishing the return within the specified extended dates, with nil interest for certain classes and a partial interest rate for taxpayers above rupees 5 crores after the initial 15-day period. The amendment was inserted into the existing interest notification and was deemed effective from 20 March 2020.