GSTR-1 filing extension for small taxpayers permits special quarterly filing procedure with specified later deadlines. Registered persons with aggregate turnover up to 1.5 crore may follow a special procedure to furnish outward supply details in FORM GSTR-1 for specified quarters; the State Government, under section 148 and superseding an earlier notification, prescribes extended time limits for those quarters and states that the special procedure or extension under sub section (2) of section 38 and sub section (1) of section 39 will be notified subsequently in the Official Gazette.