How to Do a Business Name Search in Illinois

Business Name Search in Illinois: To determine if your name is unique, you will need to search for it with the Illinois LLC Search Tool before forming an LLC or registering an assumed name.

Illinois LLC Name Search

Illinois Secretary of State requires that all business names be distinguished from any other entities within the state.

It is also important to search the Internet for a domain name that matches your desired URL.

Illinois business name search page

Illinois Business Entity Search Page

How to Find Available LLC Names

Search for an Illinois LLC name via:

  • Online database
  • Telefon

Calling the Secretary of State is a good idea, even if your name appears on the Illinois LLC search database.

Online Database

After you have determined that your corporation name complies with Illinois business name guidelines, use the Illinois LLC search tool to verify it.


For a screening of name availability, you can call the Illinois Secretary Of State at (217-524-8008).

How to check available domain names

When choosing a business name, you will need to determine if a suitable web domain is available. It is crucial to have a URL that matches your business name. This simple step can make all the difference in how potential customers find you business.

How to register your business name

Register your name

When you file your LLC application documents and create an LLC, the LLC name becomes officially registered

Register Your Name

Optionally, you can reserve your Illinois LLC name for up to 90 calendar days before you register it. This stops other businesses from using your name before you can register it.

You can file name reservations by mail at the Illinois Secretary Of State. The filing fee is $25.

Illinois Naming Requirements

Some key guidelines for Illinois LLC names include:

  • Your name must contain the phrase “limited liability corporation” or one of its abbreviations, such as L.L.C. or L.L.C. It must include “L3C” if it is a low-profit LLC.
  • If you do not register for an assumed title, your name must be the name that your LLC operates under.
  • Your name must be distinct from all other businesses in the state. This includes Illinois reserved names.

Restricted words are something to be aware of. To keep your LLC’s sounding official, these words (e.g. “FBI” and “Treasury”) are often limited.

The following restrictions apply to LLC names in Illinois:

  • You cannot use the following terms in your name: “Corporation,” “Corp.,” “Incorporated,” “Inc.,” “Inc.,” “Ltd.,” or “Limited Partnership.”
  • No word or phrase can be included in your name (e.g. “trust,” trustee,” or “fiduciary” must not be used in your name. The name of an LLC that is formed to accept or execute trusts must include the word “trust”.
  • Names may not contain words or phrases that are restricted by state statutes (e.g. LLCs are not allowed to act as banks or insurers in Illinois).

You can find more information in Illinois’ official state statutes.


Your name must be distinct from any other business name. A distinguishable name in Illinois is substantively distinct from any other business or reserved business names within the state.

These differences make it possible to distinguish a name in Illinois from one another:

  • Identifiers of business entities such as “limited”, or “liability”, or abbreviations of any of these words.
  • Articles
  • Conjunctions
  • Contractions
  • Abbreviations
  • Different tenses and numbers of the same word

Your formation filing could be rejected if you do not use a distinct name.

How can I verify if an LLC is registered in Illinois?

You can use the Illinois LLC Search tool to check if your business name appears.

For a screening of your name, you can call the Illinois Secretary-of-State at (217-524-8088)

What words are prohibited in an Illinois LLC name

It is not possible to include words in business names that suggest that the company is a bank or financial institution, or that it is affiliated with a local or state government agency.

The following terms are prohibited in Illinois LLC names:

  • “Corporation,” “Corp.,” “Incorporated,” or “Inc.,” “Ltd.,” or “Co.,”
  • Any phrase or word (e.g. Any word or phrase (e.g. trust, trustee, fiduciary), that implies or indicates that your LLC is in business as a corporate fiduciary
  • Any word or phrase that is prohibited by any state statute (e.g. LLCs aren’t allowed to operate in Illinois as banks or insurance companies)
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