I came up with the issue which IBAN didn't updated in CREMAS Inbound but which seems to be a common question around , but
Conclusion is , CREAMAS can update the IBAN successfully in the following criteria,
Field E1LFBKM - IBAN
To update the value in IBAN should be totally validate with the following fields as IBAN is a combination of below ,
BANKL - Bank Number
BANKN - Bank Account
BANKS - Bank Country
BKNOT - Bank Control Key
If these fields and whatever the value in IBAN field does not match IBAN will not updated and it willnot give you a error and IDOC will successfully will be updated.
To handle this you can use the User Exit , EXIT_SAPLKD02_001. and Function Module : CONVERT_IBAN_2_BANK_ACCOUNT to do a manual validation and change the IDOC status to a error status
