Certain business types must register with the state of Illinois, including partnerships, corporations, nonprofits and limited liability companies. An LLC is a way of doing business that provides its owners with protection from liability. The structure is suited to almost every business type except for banking and insurance. If you intend to do business in the state of Illinois, you are required to register your LLC with the state's LLC section.
Download and print two copies of form LLC-5.5, Articles of Organization.
Fill out the forms.
Mail both copies of the form, along with a check for $500 -- as of November 2010 -- to: Secretary of State Department of Business Services Limited Liability Division 501 S. Second St., Rm. 351 Springfield, IL 62756
Fill out the online Illinois tax registration form if you are going to hire employees, buy or sell products or manufacture goods.
In addition to registering with the state, you are also required to register your fictitious name with your local country clerk's office. To find a county clerk's office near you, visit the Illinois Department of Public Health's online list of county vital records websites or county clerk addresses.