Furnishing of returns requires electronic filing of periodic GST returns reporting supplies, input credit and tax by prescribed deadlines. Registered persons must electronically furnish periodic returns of supplies, input tax credit and tax payable/paid by prescribed deadlines; composition taxpayers and certain categories follow quarterly or distinct monthly timelines. The Commissioner may extend deadlines by notification. Tax due per return must be paid by the filing date. Returns are required each tax period even if no supplies occurred. Taxpayers may rectify own omissions or incorrect particulars in subsequent period returns subject to interest, within prescribed post-year cutoffs; filing is blocked if earlier returns are outstanding.