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

M8156 - Overview

• 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