Schedule C can be used by various types of businesses, including sole proprietorships and single-member LLCs (Limited Liability Companies) that are treated as disregarded entities for tax purposes. It is suitable for businesses operated by an individual without forming a separate legal entity, such as independent contractors, freelancers, and small-scale businesses. If you are unsure whether Schedule C is appropriate for your business, it is recommended to consult with a tax professional or review the IRS guidelines to determine the correct tax form to file.