Form 8288-B, Application for Withholding Certificate for Disposition by Foreign Persons of U.S. Real Property Interests, requires a U.S. Individual Income Tax Number (ITIN). The taxpayer must apply for ITIN using W7. IRS has strict supporting documents requirements for ITIN applications. Canadian taxpayers have often complained about the back and forth of the ITIN applications, or rejections due to incomplete or erroneous ITIN applications.