An i9 is a form used by employers in the United States to verify the identity and employment authorization of individuals hired for employment in the country. The form is officially called the Employment Eligibility Verification and is mandated by the Immigration Reform and Control Act of 1986. All U.S. employers must properly complete Form I-9 for each individual they hire for employment in the United States, including citizens and noncitizens. The form requires both employees and employers (or authorized representatives of the employer) to complete it. The I-9 is not required for unpaid volunteers or for contractors, but a company could still find itself liable if it contracts work to a contractor it knows either is or employs unauthorized workers. The form has been updated multiple times since it was first introduced in 1987, and only the most current version is valid for use. The USCIS updates the Form I-9 periodically, so employers should ensure they are using the most current version of the form available on the USCIS website.