Although eligibility requirements for becoming a cosmetologist vary from state to state, all states in the United States require that you have a license to work in this capacity. Some states require that you complete a closed-book written test, while others require you to complete a closed-book written and practical test. Approximately two hours are allotted for each of the written exams in Texas, Tennessee, Florida, and Pennsylvania, with additional time for the states that require the practical exam.