Input tax credit mismatch reclaimed after supplier corrects invoices in a valid return, allowing reduction of future output tax liability. System-detected mismatches causing recovery of input tax as output tax can be reclaimed once the supplier declares the missing invoice or debit note details in a valid return for the period in which the error was detected; the recipient reclaims the amount by reducing its output tax liability in a subsequent tax period, with analogous adjustments where a supplier issues a credit note and amends its return.