How To Fix JB088 - External number is not unique

SAP Error Message - Details

• Message type: E = Error

• Message class: JB - General Message Class for IS-B (Development Class JBD)

• Message number: 088

• Message text: External number is not unique

Self-Explanatory Message

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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.

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Smart SAP Assistant

• What is the cause and solution for SAP error message JB088 - External number is not unique ?

  The SAP error message JB088, which states "External number is not unique," typically occurs in the context of number ranges in SAP. This error indicates that the system has encountered a situation where an external number (such as a document number, invoice number, etc.) is not unique within the defined number range.
  Cause:
  
  Duplicate External Number: The most common cause is that the external number you are trying to use has already been assigned to another document or entry in the system.
  Number Range Configuration: The number range configuration may not be set up correctly, leading to conflicts in number assignment.
  Manual Entry: If users are manually entering external numbers, they may inadvertently enter a number that has already been used.
  Data Migration Issues: If data has been migrated from another system, there may be overlaps in the external numbers.
  
  Solution:
  
  Check Existing Numbers: Verify if the external number you are trying to use is already in use. You can do this by checking the relevant document or entry in the system.
  Use a Unique Number: If the number is already in use, you will need to generate or select a different, unique external number.
  Review Number Range Settings: Go to the number range configuration in SAP (transaction code SNRO) and ensure that the number ranges are set up correctly and that there are no overlaps.
  Adjust Number Range: If necessary, adjust the number range settings to allow for more unique numbers or to reset the range if it has been exhausted.
  Consult Documentation: Review SAP documentation or consult with your SAP administrator for specific guidance on managing number ranges and resolving conflicts.
  Check for Data Migration Issues: If this issue arose after a data migration, review the migration process to ensure that external numbers were handled correctly.
  
  Related Information:
  
  Transaction Codes: You may need to use transaction codes like SNRO (Number Range Objects) to manage number ranges or SE11 (Data Dictionary) to check the underlying tables.
  SAP Notes: Check SAP Notes for any known issues or patches related to this error message.
  User Exits or BAdIs: If you have custom developments, check if there are any user exits or BAdIs that might be affecting number assignment.
  
  By following these steps, you should be able to identify the cause of the JB088 error and implement a solution to resolve it.