SAP Message R1451 - External BP number &1 has already been assigned for business partner &2

Diagnosis
A business partner was created with an external BP number that isalready being used for one or more business partners.

System Response

  • If you create a business partner in the BP dialog with an
  • external BP number that is already being used, you can still save thebusiness partner's data.
    In this case the system issues this message as a warning.

    Note
    The following information is not relevant if you are using a CRM system.

    • If you create a business partner with an external BP number using
    • Direct Input in an ERP System and the external BP number isalready being used for one or more business partners, the businesspartner's data is still saved.
      In these cases the system issues this message as a warning.
      • If you change a business partner with an external BP number using
      • Direct Input in an ERP System and the external BP number isalready being used for one or more business partners, this message isissued as an error.
        This is the case if the field business partner (BU_PARTNER) is notfilled, and the external BP number (BU_BPEXT) is referred to as anidentifying characteristic.
        You must state the business partner number (BU_PARTNER) in order tochange the business partner in the Direct Input.

527383Direct Input/BAPIs: Use of external partner number