An ITIN is an Individual Tax Identification Number and is required to pay federal taxes regardless of a person's immigration status; this is different from a social security number, which can only be obtained by U.S. citizens. You can purchase a home with an ITIN number, but you'll need to build up your credit history. Traditional banks may be hesitant to provide you with a loan, which means you'll likely need to seek a private lender. It's also important to note that if you have an ITIN, you can only purchase a home if you intend to live in it as your primary residence. To obtain an ITIN, you'll need to submit form W7 via the IRS website.