How To Fix AR125 - Bank key contains invalid characters

AR125 - Overview

• Message type: E = Error

• Message class: AR - SSRV function module messages

• Message number: 125

• Message text: Bank key contains invalid characters

What causes this issue?

Clicking on 'Bank data' under 'Further checks' when field checks are
carried out for the various countries, activates check digit
validation. For this, a fixed entry format is necessary, depending on
the country involved. Your entries are checked automatically with a
general format check, provided the fields 'Bank key: length' and 'Bank
key: check rule' (this also applies to field checks for countries) have
been correctly maintained. If the named fields have not been correctly
maintained, the format check will check for a format with which the
check digit validation cannot be carried out.

How to fix this error?

Check your entry.
You may also need to check the settings for the field validations of
thecountries.
Possibly you also need to change the 'Bank key: length' and Bank key:
check rules' fields.
To deactivate check digit validation, cancel the 'Bank data' switch
under
'Further checks'.

Error message extract from SAP system. Copyright SAP SE.

AR125 - Details

• The SAP error message AR125, which states "Bank key contains invalid characters," typically occurs when the bank key entered in the system contains characters that are not valid according to the format expected by SAP. This can happen in various transactions where bank details are entered, such as vendor or customer master data.
  
  Cause:
  
  Invalid Characters: The bank key may contain special characters, spaces, or letters that are not allowed. For example, a bank key should typically consist of numeric digits only.
  Incorrect Format: The bank key may not conform to the expected length or format defined for the specific country or bank.
  Data Entry Errors: Manual entry errors can lead to the inclusion of invalid characters.
  
  
  Solution:
  
  Check the Bank Key: Verify the bank key you are entering. Ensure it consists only of valid characters (usually numeric) and matches the expected format for the specific country.
  Refer to Country-Specific Formats: Different countries have different formats for