Do you have to work for a company to be part of their union?

Generally, you must be employed by a company to be a member of its union, as unions typically represent the collective interests of workers at that specific workplace. However, some unions allow for associate memberships or may have broader categories for individuals not directly employed by a member company, such as retirees or those in related fields. It's best to check the specific union's bylaws for details on membership eligibility.