Yes. If you are not an employee, you are considered an independent contractor. Determining the relationship between you and your employer (or employee) can sometimes be confusing. However, put simply, if you are not paid as a W-2 employee, you are considered an independent contractor and are required to have a business license.
Fortunately, the State Department of Employment Development (EDD) has a very helpful booklet highlighting specific guidelines to follow in determining the correct relationship between you and your employer/employee. Contact EDD if you are unsure of the relationship. Once a determination has been made that your relationship is not that of an employee/employer, by default then, it is that of an independent contractor subject to a business license.