How To Fix IM156 - Partner type of the partner function entered is not allowed

IM156 - Overview

• Message type: E = Error

• Message class: IM - Maintenance notifications

• Message number: 156

• Message text: Partner type of the partner function entered is not allowed

What causes this issue?

You entered a <GL:partner_function>partner function</> that refers to a
partner type that is not allowed here. You can only
enter partner functions with type "KU" in the customer partner function,
and partner functions of type "AP" for the contact person. The following
partner types are allowed for internal partners:

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

"US" = user
"PE" = person
"O " = organizational unit
"S " = position
"LI" = vendor

System Response

How to fix this error?

Enter an allowed partner type. Check the partner determination procedure
assigned to the notification type.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message IM156 - Partner type of the partner function entered is not allowed ?

  The SAP error message IM156, which states "Partner type of the partner function entered is not allowed," typically occurs when there is a mismatch or misconfiguration in the partner function settings within the SAP system. This error can arise in various modules, such as Sales and Distribution (SD), Materials Management (MM), or others where partner functions are utilized.
  
  Cause:
  
  Incorrect Partner Function Configuration: The partner function you are trying to use is not allowed for the specific partner type in the context of the transaction you are executing.
  Missing Partner Type: The partner type that you are trying to assign to a partner function may not be defined in the system.
  Customizations: If there are customizations or enhancements in the partner function settings, they may restrict certain partner types from being used.
  Transaction-Specific Restrictions: Certain transactions may have specific rules regarding which partner types can be used with which partner functions.
  
  
  Solution:
  
  
  Check Partner Function Configuration:
  
  Go to