How To Fix M8_2128 - Differential invoicing: external document number not available

SAP Error Message - Details

• Message type: E = Error

• Message class: M8_2 - Logistics Invoice Verification

• Message number: 128

• Message text: Differential invoicing: external document number not available

What causes this issue?

You have defined checks for external document numbers in Customizing.
However, there is no external document number in the credit item of the
IDoc or SOA message.

System Response

The document was not posted.

How to fix this error?

Either deactivate the external document number check for your partner in
Customizing for <LS>Materials Management</>, under <LS>Logistics Invoice
Verification</> -> <LS>EDI</> -> <DS:SIMG.OLMROMRY>Enter Program
Parameters</> or ask your supplier to enter the external document number
required in the credit memo item of the IDoc or SOA message.

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.

Smart SAP Assistant

• What is the cause and solution for SAP error message M8_2128 - Differential invoicing: external document number not available ?

  The SAP error message M8_2128, which states "Differential invoicing: external document number not available," typically occurs in the context of differential invoicing in SAP. This error indicates that the system is unable to find the external document number that is required for processing the differential invoice.
  Cause:
  
  Missing External Document Number: The external document number that is supposed to be linked to the differential invoice is not available in the system.
  Incorrect Configuration: There may be configuration issues in the invoicing or document management settings that prevent the system from recognizing the external document number.
  Data Entry Errors: The external document number may have been entered incorrectly or may not exist in the system.
  Document Deletion: The document that the differential invoice is referencing may have been deleted or archived, making it unavailable for processing.
  
  Solution:
  
  Check External Document Number: Verify that the external document number is correctly entered and exists in the system. You can do this by checking the relevant documents in the system.
  Review Configuration: Ensure that the configuration for differential invoicing is set up correctly. This may involve checking the settings in the relevant SAP modules (e.g., MM, SD).
  Document Availability: Confirm that the document associated with the external document number has not been deleted or archived. If it has, you may need to restore it or create a new document.
  Consult Documentation: Refer to SAP documentation or help resources for specific guidance on differential invoicing and external document number requirements.
  Contact Support: If the issue persists, consider reaching out to your SAP support team or consulting with SAP experts for further assistance.
  
  Related Information:
  
  Differential Invoicing: This is a process used in SAP to handle invoicing for partial deliveries or services rendered over time. It allows for the invoicing of differences between the original invoice and subsequent adjustments.
  Transaction Codes: Familiarize yourself with relevant transaction codes such as VF01 (Create Billing Document) or VF02 (Change Billing Document) to troubleshoot and manage invoices.
  SAP Notes: Check for any SAP Notes related to this error message, as they may provide specific fixes or patches that address the issue.
  
  By following these steps, you should be able to identify the cause of the error and implement a solution to resolve it.