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Assumed Business Names

Assumed Business Name Registration

What is an Assumed Business Name?

An Assumed Business Name, also known as a DBA ("Doing Business As"), is required only for sole proprietorships and general partnerships, located in DuPage County*, to conduct business under a name other than the real name(s) of the individual(s) doing business.
All individuals registering an Assumed Business Name or D/B/A, must have valid photo identification that reflects their CURRENT address.

If you want to do business as an LLC, LLP, INC, or any type of corporation, you must register with the State of Illinois.
Click here for information for Forming an LLC/corporate entity.

To search information for Corporations, Not-for-Profit Corporations, Limited Partnerships, Limited Liability Companies, and Limited Liability Partnerships visit the Secretary of State's Business Services website.

If you are seeking information on a business license or permit, please contact the Illinois Department of Financial and Professional Regulation.
*If you are transacting/conducting business located an address outside DuPage County, you must register your Assumed Business Name or D/B/A with the County Clerk of the appropriate county.

Who Needs to Register Under the Assumed Business Name Act?

Sole proprietorships and general partnerships located in DuPage County must register with the DuPage County Clerk's Office if the name of the business is any name other than that of the owner(s).
If you are conducting business under your legal name, you do not need to register an Assumed Business Name/DBA.

Please read the statute below for all information regarding Assumed Business Names:


How Do I Register an Assumed Business Name?


Come to the DuPage County Clerk's Office, 421 N. County Farm Road, Wheaton, IL 60187, Monday-Friday, 8 a.m. to 4:30 p.m.

Please complete the Certificate of Ownership of a Business Application prior to coming to the office.

After completing the application process, the owner must then publish their assumed business notice in a local newspaper for 3 consecutive weeks.

After all 3 publications are complete, the County Clerk must receive a Certificate of Publication from the newspaper. Some newspapers will send this directly to the Clerk, but some may send it to the business owner. It is the responsibility of the business owner to ensure it is filed with the Clerk within 50 days of the file-stamp date on the Certificate. A registration is voided if no proof of publication is received within the statutory 50-day window.

After the Clerk's office receives proof of publication from the newspaper, within the deadlines, the Assumed Business Name certificate will be issued.


Fill out the application and have each owner sign and complete their respective sections. Their signatures must then be notarized and the application mailed to the Clerk's office with a check or money order made payable to the DuPage County Clerk.

The application and $10.00 check/money order payment must be mailed to:

Jean Kaczmarek
DuPage County Clerk
P.O. Box 1028
Wheaton, IL 60187

Please make sure to include your phone number on the application in the event the office needs to contact you for further information.

What is the fee to register an assumed business name?

The filing fee for an assumed business name is $10. We accept payment by cash, check, money order made payable to the DuPage County Clerk.  
We also accept credit or debit card (transaction fees apply) 

What is the process to complete the registration of an assumed business name?

The process includes publishing in a local newspaper for three consecutive weeks. Publication fees vary by newspaper. After receiving proof of publication to the County Clerk within the publication deadlines, the office will issue the Assumed Business Name certificate. It is the responsibility of the business owner to ensure it is filed with the Clerk within 50 days of the file-stamp date on the Certificate.

Duplicate assumed business name certificates can be issued for a $5 fee.

What is the process to change the registration of an assumed business name?

If the registered assumed business name is being changed, a brand new application must be completed and the same statutory publication guidelines will apply. A supplemental change to an existing assumed business name can be made to a registered assumed business name if:

  • The home address or business address of any registered owner of the business has changed. Proof of address must be provided.
  • Any registered owner of the business had a legal name change. Certified court name change documents must be provided.
  • The existing owner wishes to add an additional owner to the registration.
    Please note: Publication of a supplemental change is required when the change of ownership constitutes at least 25 percent of total ownership and the statutory publication guidelines will apply.


Useful links:

Tax Information for Businesses from the IRS
State of Illinois Business Portal
Department of Commerce bureaus and offices

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