Invoice Tax Withholding code not defaulting on Tax lines

Hi,

Please advise - what setup do we need in order to make the Invoice Tax Withholding group code in the invoice header to default into the Tax lines of the invoice?

We need the Tax Lines to also have the Tax Withholding group because Oracle does not calculate the Withholding amount if not all invoice lines have the Tax Withholding group code.

Please advise. Thanks in advance!