Return filing obligations require registered persons to submit electronic returns and remit tax within prescribed periodic deadlines. Registered persons must electronically furnish periodical returns reporting inward and outward supplies, input tax credit, tax payable and tax paid, and other prescribed particulars; returns must be filed for every tax period including nil periods, and tax due must be paid no later than the date for furnishing the return. Differentiated filing periodicity applies to specified classes (composition taxpayers, TDS deductors, input service distributors, non resident taxpayers). The Commissioner may extend deadlines by notification, rectifications of omissions are allowed in subsequent returns subject to interest and a statutory cutoff, and no later-period return may be filed while any earlier-period return is outstanding.