The sole proprietorship is the simplest business form under which one can operate a business. The sole proprietorship is not a legal entity. It simply refers to a person who owns the business and is personally responsible for its debts. A sole proprietorship can operate under the name of its owner or it can do business under a fictitious name, such as Nancy’s Nail Salon. The fictitious name is simply a trade name–it does not create a legal entity separate from the sole proprietor owner.