Submitted mandates are responded to with a reason code. Submitted eMandates do not fail. Submitted physical mandate requests can be rejected.
Note that mandate failure is different to eMandate errors.
Click here to see the full list of NACH Debit mandate response reason codes.
eMandates, once authorised by the customer, do not fail.
Physical mandates are generally rejected due to signature mismatch or invalid mandate data. This can be overcome by submitting a fresh mandate request with a suitable correction.
Physical mandates that are in Acknowledged status for 10 days or more are assumed to be 'TAT EXPIRED' i.e. The destination bank has failed to respond within the turn-around time stipulated by NPCI. It is generally not possible to resolve such cases. The best recourse is to create a new mandate or to collect payment through other means.