The IRS has outlined specific steps that you must take as an employer whenever you hire someone.  These steps include:

- Determine their eligibility
- Get their SSN and complete and submit a W-2
- Engage in employee withholding

Learn more about these requirements at: 

IRS website that outline the federal requirements for hiring employees

Determine Eligibility

You must determine that is eligible to work in the U.S. by completing the Form I-9, Employment Eligibility Verification.  See details at the IRS website. 

Social Security Number

You must verify that the employee has a valid Social Security Number.  The employee must show you his/her social security card.  If an individual does not have a SSN card they can apply for one using Form SS-5.  The ITIN is not a substitute for a SSN card.  The E-Verify system is also available for employers to check the validity of Social Security Numbers.

Employee Withholding

Employees must complete Form W-4, Employee's Withholding Allowance Certificate in order to start withholding taxes.