E-Verify works by comparing the information employees provide for Form I-9, Employment Eligibility Verification, against records available to DHS and SSA. 

E-Verify Case

Generally, if the information matches, the employee’s case receives an Employment Authorized result in E-Verify. If the information does not match, the case will receive a Tentative Nonconfirmation (Mismatch) result and the employer must give the employee an opportunity to take action to resolve the mismatch.

A DHS or SSA Tentative Nonconfirmation (mismatch) results when the information entered in E-Verify does not match DHS records or data available to SSA. A mismatch does not necessarily mean that the employee is not authorized to work in the United States.