E-Verify is an Internet-based system operated by the Department of Homeland Security (DHS) in partnership with the Social Security Administration (SSA).

The online system allows an employer to electronically verify employment eligibility of newly hired employees.

The program is free and in most states, still voluntary.

The online system allows an employer to electronically compare employee information provided on Form I-9 against SSA & DHS databases.

More than 225,000 employers, large and small, across the United States use E-Verify to check the employment eligibility of their employees, with about 1,000 new businesses signing up each week.

While participation in E-Verify is voluntary for most businesses, some companies may be required by state law or federal regulation to use E-Verify. For example, most employers in Arizona and Mississippi are required to use E-Verify. E-Verify is also mandatory for certain employers with federal contracts or subcontracts that contain the Federal Acquisition Regulation E-Verify clause.