Tax Collection at Source obligations require e commerce operators to collect, remit and report GST linked TCS and credit suppliers' ledgers. TCS under GST requires e commerce operators to collect tax on the net value of taxable supplies made through their platforms where the operator collects consideration, computed at the supplier's GSTIN level after adjusting returns. Operators must obtain TCS registration in each State/UT, remit collections within ten days after month end, file monthly FORM GSTR 8 and annual FORM GSTR 9B, and cannot pay TCS from their input tax credit. Collected amounts are credited to suppliers' electronic cash ledgers and usable against their tax liabilities; interest and penalties apply for omissions or incorrect particulars.