Contrary to popular belief, neither immigration law nor federal tax law requires an individual to possess an SSN to begin working. IRCA does not require an employee to present an SSN Card but, rather, lists the Card as a possible List C document of work authorization. Similarly, the Internal Revenue Code does not require an employee to possess an SSN to begin working. It requires only that an application for an SSN be made within seven days of commencing employment for taxable wages. 26 USC § 6011; 26 CFR § 31.6011(b)-2. Usually, the real obstacle to commencing employment is the software of a third-party payroll preparer, which cannot generate a paycheck without the number. Under these circumstances, if permitted by its system, the preparer can use a dummy SSN solely to generate a paycheck, provided the actual SSN or other required information is provided on the information returns at the time of filing. Further instructions are on the SSA website at http://www.ssa.gov/employer/