File a DBA in Illinois

If you want to do business under a different business name you’ll need to file for a DBA, or ‘Doing Business As.’ Find out more about how to get a DBA, how it affects your business, taxes and more.

What's your DBA name?

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by Sam Eichner
updated May 11, 2023 ·  2min read

What is a DBA?

If the owners of a company want to do business using a name that is different from the original name used to form the business, they must register the secondary name. For sole proprietorships and partnerships the original name is the actual name of the owner or partners.

This secondary name doesn’t replace the original name but acts as an additional, legal name for the business. This name is known by several terms such as trade name, fictitious business name and assumed name. The process for filing this name is often called filing for DBA registration, or doing business as.

For example, if “Frank’s Hot Dogs LLC” wants to do business as “Best Hot Dogs in Town” then the owners have to file a DBA.  

When you need a DBA

Under Illinois law, all businesses are required to register alternative trade names by filing for a DBA if the business seeks to operate under a different name than the name used when it was formed. In the case of a sole proprietorship, any name different than the owner’s legal name requires registration.

Setting up a DBA in Illinois

The first step in filing your DBA is to search the business names already in use in Illinois so you can determine if the name you want to use is available. That database can be found here and is a useful tool in clearing the proposed assumed name or DBA. Note: phrases such as “incorporated,” “inc.” etc. cannot be used, nor can deceptive or vulgar phrases.

Once a business name is chosen, you fill out a Certificate of Assumed Name form and file it with the county clerk in the county where business is located. Each county has its own specific requirements for filing this paperwork, but most accept the the online filing options found at

Note: Some counties require that the notarization and publication of the paperwork. This means a notary public will have to officially sign your form. You can find out more about notarization here. If you have to publish your DBA registration, that means you’ve got to have official notice printed in a newspaper in the county where the business operates. If required in your county, this publication must happen no more than 15 days after you file the DBA.

The paperwork will ask:

  • What is the assumed business name (trade name) on the DBA registration

  • The name and address of the business owner(s)

  • The company’s principal business address

  • Proof of notarization and publication, if required

Assumed names are also liable to expire after five years. You can go here for Corporate Assumed Name renewal. Also check with your county clerk for local requirements for renewing your assumed name.

Tax Considerations

Getting an assumed name for your company by filing a DBA registration will not change how your company is taxed.

If you’re ready to file a DBA, LegalZoom can help you get started today. We can help you file the paperwork with your state and can get you in touch with an attorney or tax professional to answer specific questions.


About the Author

Sam Eichner

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This portion of the site is for informational purposes only. The content is not legal advice. The statements and opinions are the expression of the author, not LegalZoom, and have not been evaluated by LegalZoom for accuracy, completeness, or changes in the law.