How To Fix FMKU064 - This external document number is already in use

SAP Error Message - Details

• Message type: E = Error

• Message class: FMKU - FM budgeting, kernel utilities

• Message number: 064

• Message text: This external document number is already in use

Self-Explanatory Message

Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of messages in the SAP system have a message text, however this is frequently insufficient to comprehend or resolve the problem.

To make things easier, more detailed information is frequently added to describe the issue, how to fix it, and the necessary steps or configuration modifications.

Unfortunately, there isn't any extra information in this error notice.

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Smart SAP Assistant

• What is the cause and solution for SAP error message FMKU064 - This external document number is already in use ?

  The SAP error message FMKU064, which states "This external document number is already in use," typically occurs in the context of financial transactions, particularly when dealing with document management or posting financial documents. This error indicates that the external document number you are trying to use has already been assigned to another document in the system, leading to a conflict.
  Cause:
  
  Duplicate Document Number: The external document number you are trying to enter has already been used for another transaction or document in the system.
  Configuration Issues: There may be settings in the system that do not allow for the reuse of external document numbers.
  Data Entry Error: The user may have mistakenly entered the same document number that was previously used.
  
  Solution:
  
  Check Existing Documents: Verify if the external document number is indeed in use by searching for it in the relevant transaction or document management system. You can use transaction codes like FB03 (Display Document) to check if the document exists.
  Use a Unique Document Number: If the document number is already in use, you will need to generate a new, unique external document number for your transaction.
  Review Configuration Settings: If you believe that the document number should be reusable, check the configuration settings in the SAP system related to document number assignment. This may involve consulting with your SAP administrator or functional consultant.
  Consult Documentation: Review any relevant documentation or guidelines provided by your organization regarding the use of external document numbers to ensure compliance with internal processes.
  
  Related Information:
  
  Transaction Codes: Familiarize yourself with transaction codes like FB03 (Display Document), FBL1N (Vendor Line Item Display), or FBL3N (G/L Account Line Item Display) to investigate existing documents.
  SAP Notes: Check SAP Notes for any known issues or patches related to this error message. SAP Notes can provide additional insights or solutions.
  User Authorization: Ensure that you have the necessary authorizations to create or modify documents in the system, as lack of permissions can sometimes lead to unexpected errors.
  
  If the issue persists after trying the above solutions, it may be beneficial to reach out to your SAP support team or consult with an SAP expert for further assistance.