How To Fix VFKK121 - Billing type of reversal &1 or original &2 not of type invoicing order

VFKK121 - Overview

• Message type: E = Error

• Message class: VFKK -

• Message number: 121

• Message text: Billing type of reversal &1 or original &2 not of type invoicing order

What causes this issue?

The billing type &V2& and the assigned reversal billing type &V1& have
to be treated the same by FI-CA invoicing. That means that they both
have to be processed with an FI-CA invoicing order, or they both have to
be posted directly as FI-CA documents.

How to fix this error?

Change the settings in posting area 1205 in Customizing for Contract
Accounts Receivable and Payable under <LS>Integration -> Sales and
Distribution -> Define Settings for Transfer to Invoicing</>.

Error message extract from SAP system. Copyright SAP SE.

VFKK121 - Details

• The SAP error message VFKK121 indicates that there is an issue with the billing types being used in a reversal or original billing document. Specifically, it suggests that the billing type of the reversal document (denoted as &1) or the original document (denoted as &2) is not of the type that is expected for invoicing orders.
  
  Cause:
  
  Incorrect Billing Type: The billing type used for the reversal or original document is not configured as an invoicing order type in the system. This can happen if the billing type is set up incorrectly in the configuration or if the wrong billing type is being used in the transaction.
  Document Flow Issues: The document flow may not be correctly established, leading to inconsistencies in the billing types.
  Customizations: If there are custom developments or modifications in the billing process, they may not align with the standard expectations of billing types.
  
  
  Solution:
  
  
  Check Billing Type Configuration:
  
  Go to the configuration