Tax Collected at Source reporting requires monthly GSTR-8 filings and annual reconciliation, with limited rectification and supplier credit. E-commerce operators must file a monthly Form GSTR-8 within ten days after month-end reporting outward and inward supplies and the TCS collected; an annual Form GSTR-9B reconciles these particulars for the financial year. Errors in monthly returns may be corrected in the next monthly statement on discovery subject to interest, but corrections are barred after the earlier of 30th November following year-end or the filing date of the annual statement. TCS collected by the operator is creditable in the supplier's electronic cash ledger.