A social security number is required to apply for credit, including bank loans and credit cards. This is because these services require a credit check, which can only be authorized with a social security number.
Those who are trying to apply for credit and don't have a social security number can get one through the United States Social Security Administration. In order to get a number, it is necessary to provide proof of identity to the Social Security office using approved documents such as a passport or birth certificate. An in-person interview is also required for individuals over the age of 12 who are applying for a number.