Furnishing of returns requires registered persons to file prescribed electronic GST returns and pay tax by specified deadlines. Every registered person must electronically furnish periodic returns of supplies, input tax credit, tax payable and tax paid by prescribed deadlines; composition taxpayers, TDS deductors, Input Service Distributors and non resident taxpayers have specified periodic filing timelines. The Commissioner may extend deadlines by notification. Tax due must be paid by the return due date and returns must be filed for every tax period, including nil periods. Post filing omissions or incorrect particulars may be rectified in a subsequent return subject to interest and an absolute cut off tied to the September return, the second quarter after the financial year end, or the filing of the annual return. Filing is barred if prior period returns remain unfiled.