Message type: E = Error
Message class:  FKK_ID_BR - Message class for Brazil Withholding tax functionalities 
Message number: 308
Message text: Incorrect assignment of tax calculation method
You are trying to assign a tax calculation method to a correction tax
code or catch up tax code. This is incorrect as you can only assign tax
calculation method to a supplement tax code and not to a correction tax
code or catch up tax code. A correction tax code or catch up tax code is
used internally for withholding tax calculation and you cannot assign a
tax calculation method to it.
System will not allow you to save your data.
Assign tax calculation method to a valid supplement tax code.
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.
The SAP error message FKK_ID_BR308, which indicates "Incorrect assignment of tax calculation method," typically arises in the context of the SAP Convergent Charging (SAP CC) or SAP Contract Accounts Receivable and Payable (SAP FI-CA) modules. This error is related to the configuration of tax calculation methods and their assignment to specific business processes or transactions.
Cause: Incorrect Configuration: The tax calculation method may not be correctly configured in the system. This could involve incorrect settings in the tax calculation procedure or the assignment of tax codes. Inconsistent Data: There may be inconsistencies in the master data or transaction data that lead to the system being unable to determine the correct tax calculation method. Missing Assignments: The tax calculation method may not be assigned to the relevant business transactions or document types. Version Mismatch: If there are multiple versions of tax calculation methods, the system may be trying to use an outdated or incorrect version.
Solution: Check Configuration:
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