How To Fix M8156 - Use either a specific tax code or '**' only

SAP Error Message - Details

• Message type: E = Error

• Message class: M8 - Invoice Verification/Valuation

• Message number: 156

• Message text: Use either a specific tax code or '**' only

What causes this issue?

In transactions subject to withholding tax, the system can only check
and calculate the input tax correctly if all the supplier items have a
tax code or <LB>**</> is used for all items.

How to fix this error?

Change the supplier document items accordingly.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message M8156 - Use either a specific tax code or '**' only ?

  The SAP error message M8156 ("Use either a specific tax code or '' only") typically occurs in the context of material management and inventory transactions, particularly when dealing with tax codes in purchasing documents or inventory postings. This error indicates that the system requires a specific tax code to be used for the transaction, or it allows the use of a wildcard ('') to represent all tax codes, but not both at the same time.
  Cause:
  
  Incorrect Tax Code Configuration: The tax code used in the transaction may not be valid or properly configured in the system.
  Mixed Use of Tax Codes: The transaction may be attempting to use both a specific tax code and the wildcard '**', which is not allowed.
  Master Data Issues: The material master or vendor master data may not have the correct tax information set up.
  Transaction Type Restrictions: Certain transaction types may have restrictions on how tax codes can be applied.
  
  Solution:
  
  
  Check Tax Code: Verify that the tax code being used in the transaction is valid and correctly configured in the system. You can do this by checking the tax code settings in the SAP configuration (transaction code OB40 for tax codes).
  
  
  Use Specific Tax Code or Wildcard: Ensure that you are using either a specific tax code or the wildcard '**', but not both. If you need to apply a specific tax code, remove the wildcard from the transaction.
  
  
  Review Master Data: Check the material master and vendor master records to ensure that the tax information is correctly maintained. You can use transaction codes like MM03 (Material Master Display) and XK03 (Vendor Master Display) to review the relevant data.
  
  
  Consult Configuration: If you have access to the configuration settings, review the settings related to tax determination in the SAP system. This may involve checking the tax classification settings for materials and vendors.
  
  
  Testing: After making the necessary changes, test the transaction again to ensure that the error is resolved.
  
  
  Related Information:
  
  SAP Notes: Check for any relevant SAP Notes that may provide additional insights or solutions for this specific error message.
  Documentation: Refer to SAP documentation regarding tax code configuration and material management processes for further understanding.
  User Forums: Consider searching or posting in SAP community forums for additional user experiences and solutions related to this error.
  
  If the issue persists after following these steps, it may be beneficial to consult with your SAP support team or a functional consultant who specializes in the relevant area.