How To Fix 29123 - Sub-item number has already been assigned

SAP Error Message - Details

• Message type: E = Error

• Message class: 29 - Bills of Material

• Message number: 123

• Message text: Sub-item number has already been assigned

What causes this issue?

You want to create a sub-item for an existing item.
The item number you entered has already been assigned.
Sub-items are uniquely identified within the item by the sub-item
number, so each sub-item number can only be assigned once.

How to fix this error?

Enter a sub-item number which has not yet been assigned.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message 29123 - Sub-item number has already been assigned ?

  The SAP error message 29123, which states "Sub-item number has already been assigned," typically occurs in the context of materials management or inventory management when dealing with sub-items in a bill of materials (BOM) or during the creation of purchase orders, production orders, or similar transactions.
  Cause:
  This error usually arises when:
  
  Duplicate Sub-item Assignment: You are trying to assign a sub-item number that has already been assigned to another item or entry in the system.
  Incorrect Data Entry: There may be a mistake in the data entry where the same sub-item number is being reused unintentionally.
  Configuration Issues: There might be issues in the configuration of the material master or BOM that allow for duplicate entries.
  
  Solution:
  To resolve this error, you can take the following steps:
  
  
  Check Existing Assignments:
  
  Review the existing sub-item numbers in the relevant transaction (e.g., BOM, purchase order) to ensure that the sub-item number you are trying to assign is not already in use.
  Use transaction codes like CS03 (Display BOM) or ME23N (Display Purchase Order) to check for existing assignments.
  
  
  
  Use a Unique Sub-item Number:
  
  If the sub-item number is already assigned, choose a different, unique sub-item number for your current transaction.
  
  
  
  Review Configuration:
  
  If you suspect a configuration issue, consult with your SAP administrator or a functional consultant to review the settings related to sub-item assignments in the material master or BOM configuration.
  
  
  
  Data Cleanup:
  
  If there are orphaned or incorrect entries in the system, consider cleaning up the data to remove duplicates or incorrect assignments.
  
  
  
  Consult Documentation:
  
  Refer to SAP documentation or help files for specific guidance related to the transaction you are working on, as there may be additional context or steps required.
  
  
  
  Related Information:
  
  Transaction Codes: Familiarize yourself with relevant transaction codes such as CS01 (Create BOM), CS02 (Change BOM), and ME21N (Create Purchase Order) to navigate and troubleshoot effectively.
  SAP Notes: Check SAP Notes for any known issues or patches related to this error message. You can search the SAP Support Portal for specific notes that might address this error.
  User Permissions: Ensure that you have the necessary permissions to create or modify the entries you are working with, as permission issues can sometimes lead to unexpected errors.
  
  If the problem persists after following these steps, it may be beneficial to engage with your SAP support team for further assistance.