You do not have to take any formal action to form a sole proprietorship. As long as you are the only owner, this status automatically comes from your business activities. In fact, you may already own one without knowing it. If you are a freelance writer, for example, you are a sole proprietor.
But like all businesses, you need to obtain the necessary licenses and permits. Regulations vary by industry, state and locality. Use the Licensing & Permits tool to find a listing of federal, state and local permits, licenses and registrations you’ll need to run a business.
If you choose to operate under a name different than your own, you will most likely have to file a fictitious name (also known as an assumed name, trade name, or DBA name, short for “doing business as”). You must choose an original name; it cannot already be claimed by another business.