According to the IRS, a sole proprietorship is the most common form of business organization. Easy to form, it is any unincorporated business owned and controlled entirely by one individual. In general, for Maryland and federal purposes the owner is personally responsible for all financial obligations and debts of the business.
Sole proprietors can operate any kind of business as long as it is a business and not an investment or hobby. It can be full or part-time. Every sole proprietor is required to keep business records to comply with federal and Maryland state tax law.
Tax information for sole proprietors may be found under Sole Proprietorships or in the Tax Information section under Individuals Income Tax section. For federal information on sole proprietors see IRS web site.