Any employer with more than four employees is subject to the Illinois Minimum Wage Law. 820 ILCS 105/3(d). Beyond that, we cannot comment on whether you would be violating that law (or federal law) by compensating an employee with a small salary plus commissions. However, we note that the Illinois Department of Labor provides FAQs on Minimum Wage/Overtime issues. Also, the U.S. Department of Labor maintains a webpage on commission compensation, as well as a compliance page on commissions.