4. Employee’s Social Security Number (SSN)
You’re required to get each employee’s name and SSN and to enter them on Form W-2. An employee’s SSN consists of nine digits arranged as follows: 000-00-0000. This requirement also applies to resident and nonresident alien employees. You should ask your employee to show you their social security card, but the employee isn’t required to show the card if it isn’t available. However, if an employee can’t provide their social security card, you should verify their SSN and their eligibility for employment as discussed later in this section under Verification of SSNs .