GST return filing restriction bars GSTR-1 details where GSTR-3B remains unfurnished for the preceding period. The Uttarakhand GST (Second Amendment) Rules, 2021 retrospectively commence from 1 January 2021 and insert a restriction in rule 59 on furnishing outward supply details in FORM GSTR-1 and the invoice furnishing facility. A registered person cannot file these details if FORM GSTR-3B for the preceding period has not been furnished, including quarterly filers and persons subject to the rule 86B restriction on use of the electronic credit ledger.