What should I do if I do not have a Social Security number?
You should apply for a Social Security number (SSN) from the Social Security Administration. If you do not qualify for a SSN and were issued an Individual Taxpayer Identification Number (ITIN) by the IRS, write your ITIN on Line A of the Form IL-1040, Individual Income Tax Return, in place of a SSN. You cannot file your IL-1040 with "Applied For" listed in the SSN field. You must wait until you receive either your SSN or ITIN before filing with Illinois.