Registering Your Business

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Doing Business As/DBA/Assumed Name Notice

A fictitious name filing, also known as Doing Business As or DBA, allows you to create name for your business that is different than your personal name, the names of your partners or the officially registered name of your LLC or corporation. When a business name is different from the owner(s) full legal name(s), the Illinois Assumed Name Act requires sole proprietorships and general partnerships to register with their local county clerk’s office. Corporations, LLCs, LLPs, and limited partnerships register an assumed name as part of their required business filings with the Illinois Secretary of State.

Registering your business name under the Assumed Business Name Act, does not prevent anyone from using your business name. The only way to prevent someone from using your business name is to file as a corporation or have a trademark for your name.

WHO MUST FILE: Anyone using a name (other than his/her own personal name, i.e. John Doe or Sally Smith) for his/her business. Note: By adding any word to your own personal name constitutes an assumed name (i.e. John Doe Company or Sally Smith Computer Service).

HOW TO FILE: Illinois State Law requires that the Notice shall be published in a newspaper of general circulation within the county in which the Certificate is filed. Such notice shall be published once a week for three consecutive weeks.

Professional Licensing

The Illinois Department of Professional Regulation (IDFPR) is the main licensing agency for the State of Illinois for most professions. Individuals must be licensed prior to conducting business as one of the listed professions.

Business Tax Registration


A Federal Employment Identification Number, also known as a Federal Tax Identification Number or FEIN, and is used to identify a business entity.  This number is required if your business is a Partnership, LLC or Corporation or if you are a Sole Proprietor that has employees.


You must register with the Illinois Department of Revenue if you conduct business in Illinois, or with Illinois customers.


Some towns in southern Illinois require local registration. Be sure to check with your City Hall first.

Have additional questions about starting your business? Contact the Illinois Small Business Development Center (SBDC) at Southern Illinois University for a confidential business consultation at no charge to you. Call (618) 536-2424 to set up an appointment.