Scenario Required handling
Original 0100 / A authorization found Match the reversal to the original authorization and release or adjust the related blocked amount.
Original authorization not found Store the reversal as unmatched and process it according to your reconciliation or exception-handling rules.
Full reversal If Txn_Amt in the reversal matches Txn_Amt in the original authorization, unblock the amount originally blocked.
Partial reversal Release or adjust only the applicable reversal amount.
Related 0120 / J authorization advice exists Apply the advice block update before applying the reversal.
Duplicate reversal Do not release or adjust funds again. Return the same logical acknowledgement.
Auth_Code_DE38 is 000000 Treat it as blank for matching purposes.
0400 / D or 0420 / D received Treat both as reversal advice in practice; do not decline the reversal.