Late fee cap for GSTR 3B filings limits per day charges and reduces liability for nil tax returns. The Central Government limits the late fee for delayed filing of FORM GSTR-3B from October 2017: where tax is payable, late fee in excess of a specified daily amount is waived; where total central tax payable is nil, late fee in excess of a lower specified daily amount is waived, thereby capping per day late fee exposure for registered persons.