W-9 Forms W-9 Forms...Ours and Theirs - If a Vendor requests a UAHuntsville W-9 Form, the form is available on our website. Feel free to either direct the Vendor to our website or you can send them a form. See the link below for our W-9 Form. As of January 1, 2011, we are required by law to obtain a completed W-9 form from a Vendor in order to make payments to that Vendor. Federal regulations require up to a 28% tax withholding on all reportable payments unless the Vendor provides this information. Therefore, if you are dealing with a new Vendor and are requesting a quote, invoice, or other documentation from them, it would be helpful if you would also request their W-9 form. If they don't already have a form, we have blank forms on our website. See the link below for the blank W-9 Form to send to a Vendor. UAHuntsville W-9 FormRequest for Taxpayer Identification Number (W-9) Form