How To Fix CNV_20000254 - New accounting number &1 already exist in CoCod &2

CNV_20000254 - Overview

• Message type: E = Error

• Message class: CNV_20000 - Messages for fiscal year change

• Message number: 254

• Message text: New accounting number &1 already exist in CoCod &2

What causes this issue?

Given <ZH>prefix </> has been concatenated with the accounting document
(using external number ranges) which will result in an issue with
duplicate records during the conversion because:
The new accounting number &V1& is already present in company code &V2&
While doing mapping using the prefix, as soon as the system finds any
one document that already exists in the database it is logged as an
error. The remaining mapped accounting documents using that prefix are
not checked which helps to prevents runtime as short as possible.

How to fix this error?

Re-execute the activity and assign a unique prefix.

Procedure for System Administrators

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

Error message extract from SAP system. Copyright SAP SE.

CNV_20000254 - Details

• The SAP error message CNV_20000254 indicates that there is an attempt to create a new accounting number (or account) that already exists in the specified company code (CoCod). This error typically arises during data migration or conversion processes, particularly when using SAP's Migration Cockpit or during the execution of a conversion program.
  
  Cause:
  
  
  Duplicate Account Numbers: The primary cause of this error is that the accounting number you are trying to create already exists in the specified company code. This can happen if:
  
  The data being imported or converted contains duplicate entries.
  There was a previous migration or data load that created the account before the current attempt.
  
  
  
  Incorrect Mapping: If the mapping of accounts from the legacy system to the new system is not done correctly, it may lead to attempts to create accounts that already exist.
  
  
  Data Integrity Issues: There may be issues with the integrity of the data being migrated, such as missing