The IRS reuqires that Banks withhold 28% of any interest income earned on an account if the following occurs: (1) a W-9 Certification is not provided by the taxpayer, (2) the IRS notifies Discover Bank that the TIN provided is incorrect, or (3) if the taxpayer has been notified by the IRS that he/she is subject to backup withholding. If an account is opened online, the W-9 is executed electronically during the online application process. If an account is opened by phone or mail, the customer is required to execute a paper signature card which contains the W-9 form.