I am a tax analyst for a financial institution. We have engaged in a contract to do businss in Hawaii's deferred compensation plan with our subsidiary. Tax clearance is needed for this (Form A-6), but is also form 8821 needed. If necessary I would try to avoid this form based on trying to have information released on the parent or subs. we need to get an approval stamp from the IRS Would a W-9 suffice as good standing to get an approval stamp for the IRS.