How To Fix RP434 - External person ID &1 is already used for another personnel number

RP434 - Overview

• Message type: E = Error

• Message class: RP - Error Messages for Infotype Module Pools

• Message number: 434

• Message text: External person ID &1 is already used for another personnel number

What causes this issue?

The system attempts to generate the external person ID in <ZK>infotype
0709</> but determined the person ID &1 because of the generation rule
defined in Customizing.
However, this value is already being used for another person.
Since the external person ID must be unique, the value for this current
personnel number remains empty.

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?

Check the personnel numbers that use the same external person ID and
correct the external person ID manually in <ZK>infotype 0709</>.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.

RP434 - Details

• The SAP error message RP434 indicates that the external person ID you are trying to use is already associated with another personnel number in the system. This typically occurs during the creation or modification of employee records in the SAP Human Capital Management (HCM) module.
  
  Cause:
  
  Duplicate External Person ID: The external person ID you are trying to assign to a new personnel number is already linked to an existing personnel number. This can happen if:
  The same external ID is mistakenly assigned to multiple personnel records.
  Data migration or import processes have led to duplicate entries.
  An employee is being re-hired or transferred, and the external ID is not being handled correctly.
  
  
  
  
  Solution:
  
  
  Check Existing Personnel Numbers: 
  
  Use transaction codes like PA20 (Display HR Master Data) or PA30 (Maintain HR Master Data) to check if the external person ID is already assigned to another personnel number.
  If you find that the external ID is indeed linked to