Challan correction mechanism permits limited corrections for allocation errors while denying tax administration GSTIN amendment powers. Challan correction mechanism is limited to operational payment errors: no administrative correction for errors in GSTIN since CIN and bank confirmation ensure correct credit and the authorized representative is accountable to the taxpayer; banks may rectify wrong major-head postings before day-end, otherwise normal reconciliation processes apply; overpayments are addressed by refund or carry-forward; and with a maintained cash ledger the 'Tax period' and 'purpose' fields will not be captured in challans, so no correction mechanism is provided for them.