Tax Collected at Source reporting: e commerce operators must discharge full TCS liability before filing the return. The return requires e commerce operators to report Tax Collected at Source by supplier GSTIN and recipient type, showing gross supplies, returns, net amounts and tax components for integrated, central and state/UT taxes; filing is conditional on full discharge of TCS liability, amendments to prior statements must present original and revised details, TCS entries flow to recipients' purchase ledger on filing, and refunds from the electronic cash ledger are allowed only after all period TCS liabilities are discharged, with the cash ledger debited for such refunds.