Tax code & may not contain a nondeductible portion

What causes this issue?

In the case of direct postings to tax accounts, no tax codes
containing a nondeductible portion to be distributed may be used.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

Please use another tax code. You might have to define a separate
tax code, that does not contain a nondeductible portion, for direct
postings to a tax account.

Error message extract from SAP system. Copyright SAP SE.