It is unfortunately not always possible to successfully complete a transaction. A direct debit payment can fail for a number of reasons. A transaction can be rejected until 5 working days after the direct debit date. When a direct debit fails, Mollie informs you via the webhook.

Via our payments API you can retrieve the reason code; a code that indicates the reason for the rejection. The following reasons are possible:

Reason code   Reason   Follow-up action   Comments
AC01   IBAN incorrect or unknown   Ask consumer for correct account number.  
AC04   Holder has closed account   Ask consumer for different account.  
AC06   Account blocked for direct debit   Ask consumer for different account.  
AG02   Incorrect information   Resubmit the transaction with correct information.   You stated FRST when it should have been an RCUR transaction (or vice versa), or you failed to use a unique mandate reference.
AM04   Insufficient funds   Contact the consumer and/or try again.   Can also be reported as a MS03.
MD01   Invalid mandate   Resubmit the transaction, only this time with FRST or contact the consumer.   Transaction was RCUR but there never was a FRST, mandate has expired (after 36 months), or there is no mandate.
MD06   Payment reversal   Contact the consumer.   Can take place within an 8-week period.
MD07   Customer has died   Do not carry out any more direct debits.   In this case, some banks report MS03.
MS02   Transaction refused   Contact the consumer.   The consumer has refused the transaction in advance.
MS03   Other reason   Contact the consumer.   Can also be the result of insufficient funds, transaction refusal, etc.
SL01   Refused by debit bank   Contact the consumer.   The account could be blocked for direct debit, or a limit has been reached, prompting the consumer's bank to refuse the transaction.


  • These are the most common reasons. Officially, there are a few more reason codes, but those are in practice almost never sent.
  • Experience has shown that MS03 is frequently used for a variety of reasons, for instance in case of insufficient funds. The bank then sends an MS03 instead of an AM04.


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