How To Fix W4109 - &: & MPN material master record exists

SAP Error Message - Details

• Message type: E = Error

• Message class: W4 - Messages for material discontinuation

• Message number: 109

• Message text: &: & MPN material master record exists

What causes this issue?

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

System Response

How to fix this error?

Delete the <DS:GLOS.3526C061AFAB52B9E10000009B38F974>MPN</> material
master record. You can then archive the material.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message W4109 - &: & MPN material master record exists ?

  Certainly! Here's a detailed explanation for the SAP error message:
  
  SAP Error Message:
  W4109 & : & MPN material master record exists
  
  Meaning / Cause:
  
  This warning message indicates that a Material Master Record already exists for the given MPN (Manufacturer Part Number).
  The system is trying to create or assign a material master record with an MPN that is already linked to another material.
  This typically happens during material creation or when assigning/changing the MPN field in the material master.
  The MPN is expected to be unique or at least not duplicated in certain business contexts or configurations.
  
  
  When does it occur?
  
  When you try to create a new material with an MPN that is already assigned to another material.
  When you try to update/change the MPN field in an existing material master to a value that already exists for another material.
  In some SAP systems, the MPN field is used as a unique identifier for materials from a manufacturer, so duplicates are flagged.
  
  
  Solution / How to resolve:
  
  
  Check existing materials with the same MPN:
  
  Use transaction MM03 (Display Material) or MM04 (Change Material) to check the material master records.
  You can also use a report or query to find all materials with the same MPN.
  For example, use transaction SE16N on table MARC or MARA or the custom field table where MPN is stored.
  
  
  
  Verify if duplication is allowed:
  
  Confirm with your business process or master data governance if multiple materials can share the same MPN.
  If duplicates are allowed, the warning can sometimes be ignored or the configuration adjusted.
  
  
  
  Correct the MPN:
  
  If the MPN is incorrectly assigned, update the material master to use the correct MPN.
  If you are creating a new material, assign a unique MPN.
  
  
  
  Adjust system configuration (if applicable):
  
  The warning is controlled by a validation or user-exit/custom code.
  Check if there is a custom validation or user-exit (e.g., in MM01, MM02) that checks for MPN uniqueness.
  If the business allows duplicates, this validation can be modified or deactivated by your SAP technical team.
  
  
  
  Consult with Master Data Governance team:
  
  If you are unsure about the MPN assignment rules, consult your master data team or SAP support.
  
  
  
  
  Additional Information:
  
  MPN (Manufacturer Part Number) is often stored in a custom field or in standard fields like Basic Data 2 tab in material master.
  The exact field and table depend on your SAP implementation and industry solution.
  This message is a warning (W), not an error, so it may allow you to proceed but is meant to alert you to potential duplicates.
  If you want to suppress this warning, you need to check the message control configuration or custom code.
  
  
  Summary:
  
  
  
  Aspect
  Details
  
  
  
  
  Message
  W4109 & : & MPN material master record exists
  
  
  Cause
  MPN already assigned to another material
  
  
  Effect
  Warning about duplicate MPN
  
  
  Solution
  Check existing materials, correct MPN, or adjust config
  
  
  Transaction
  MM01, MM02, MM03, SE16N
  
  
  
  
  If you provide the exact context (e.g., transaction, field, or custom developments), I can help you with more precise steps.
  
  Let me know if you need help with the exact table or code to find duplicates!