How To Fix FKKBIX2012 - Item for source trans. &1 is a duplicate according to check schema &2

FKKBIX2012 - Overview

• Message type: E = Error

• Message class: FKKBIX2 - Billing in Contract Accounts Receivable and Payable

• Message number: 012

• Message text: Item for source trans. &1 is a duplicate according to check schema &2

What causes this issue?

For the item being transferred of business partner &v3& with source
transaction &v1&, there is an additional item being transferred, which,
according to the <DS:DE.BIT_DCFIELD_KK>comparison fields</> entered in
<DS:DE.BIT_DCSCHEMA_KK>check schema</> &v2& for the duplicate check, is
identical.

System Response

The treatment of the item being transferred is based on
<DS:DE.BIT_DCPROCRULE_KK>processing rule</> &v4&.
The processing rule was specified in the <DS:DE.BIT_DCFUNCNAME_KK>
function module</> entered in schema &v2&.

How to fix this error?

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

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.

FKKBIX2012 - Details

• The SAP error message FKKBIX2012 indicates that there is a duplicate item in the context of a source transaction, which is being checked against a specified check schema. This error typically arises during the processing of financial documents, particularly in the context of invoice verification or payment processing.
  
  Cause:
  The error occurs when the system detects that an item being processed (identified by the source transaction number) is already present in the document or transaction being validated. This can happen due to several reasons:
  
  Duplicate Entries: The same invoice or payment document has been entered multiple times.
  Incorrect Configuration: The check schema may be configured in a way that does not allow for certain duplicates, even if they are valid in other contexts.
  Data Entry Errors: Manual data entry mistakes can lead to the same item being entered more than once.
  
  
  Solution:
  To resolve the FKKBIX2012 error, you can take the following steps:
  
  
  Check for Duplicates:
  
  Review the transaction