How To Fix EK408 - A cost element exists for G/L account &1. CO account assignment required

EK408 - Overview

• Message type: E = Error

• Message class: EK - IS-U Accounts Receivable and Payable

• Message number: 408

• Message text: A cost element exists for G/L account &1. CO account assignment required

What causes this issue?

The specified G/L account is a cost component, but you did not enter an
auxiliary account assignment (cost center, etc.).
When a posting is made to this account, an appropriate auxiliary
account assignment is required, and must come from te respective
<DS:GLOS.contract>contract</> kommen.

System Response

How to fix this error?

Make sure that the involved contracts have an appropriate auxiliary
account assignment or enter a default value here.

Error message extract from SAP system. Copyright SAP SE.

EK408 - Details

• The SAP error message EK408 indicates that there is a cost element associated with a General Ledger (G/L) account, and that a cost object (such as a cost center, internal order, or project) must be assigned to the transaction. This error typically occurs when you are trying to post a transaction that requires a cost assignment, but the necessary cost object is not provided.
  
  Cause:
  
  Cost Element Configuration: The G/L account you are trying to use is configured as a cost element in the Controlling (CO) module. This means that any postings to this account must have a corresponding cost assignment.
  Missing Cost Assignment: The transaction you are attempting to post does not include a cost assignment (e.g., cost center, internal order, etc.), which is required for accounts that are linked to cost elements.
  
  
  Solution:
  To resolve the EK408 error, you can take the following steps:
  
  
  Check the G/L Account:
  
  Go to the G/L account in the