Illinois LLC Name Search

How to Do a Business Name Search in Illinois

Selecting the right name is an essential first step for your Illinois LLC, requiring you to ensure the name’s availability. Searching the Illinois entity database is vital to avoid infringing on existing business names and intellectual property rights within the state.

Our Illinois LLC name search guide offers essential tips on checking LLC name availability, reservation, and registration, helping you secure a unique and compliant business identity efficiently.

Business Entity Search in Illinois: How To Look Up an LLC in Illinois? (Summary)

Top view of a laptop with someone doing an Illinois LLC name search online.

Check Illinois Business Name Search Availability

You can follow these steps:

  1. Go to the Illinois entity database search: On the homepage, locate the “Business Services” section and click on it.
  2. In the Business Services section, you will find various options. Choose “Business Name Availability” or a similar option.
  3. You will be directed to a search page where you can enter the desired business name. Enter the name you want to search and click on the “Search” button.
  4. The search results will display whether the business name is available or already registered by another entity in the state of Illinois.
  5. If the business name is available, you can proceed with registering it. If it is already taken, you will need to choose a different name or modify the existing name to make it unique.

Please note that the exact steps and links may change over time. Therefore, it is recommended to verify the current process by visiting the official website of the Illinois Secretary of State: or searching for “Illinois Secretary of State business name availability” on a search engine to get the most up-to-date information.

What is an Illinois Business Entity?

An illustration of someone searching online for the definition of an Illinois business entity.

An Illinois business entity refers to an organization that is legally recognized and registered to conduct business in the state of Illinois. These entities are created and managed according to Illinois state law, with the Illinois Secretary of State overseeing their formation and registration.

The types of business entities you can establish in Illinois are similar to those in most other U.S. states and include:

  1. Sole Proprietorship: This is the simplest form of business structure, owned and operated by one individual. The owner is personally liable for all business debts and obligations.
  2. Partnership: This includes general partnerships, limited partnerships, and limited liability partnerships. A partnership involves two or more people sharing the profits and losses of a business.
  3. Corporation: This is a legal entity separate from its owners (shareholders), providing them with personal liability protection. There are two types of for-profit corporations: C corporations and S corporations. Non-profit corporations can also be formed.
  4. Limited Liability Company (LLC): This is a hybrid structure that combines the legal protections of a corporation with the tax advantages and operational flexibility of a partnership.

Illinois Secretary of State Entity Search

When setting up a business entity in Illinois, the necessary paperwork (such as Articles of Incorporation for a corporation or Articles of Organization for an LLC) must be filed with the Illinois Secretary of State. The state also requires payment of specific filing fees, which vary depending on the type of entity.

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.

By Telephone

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

Man with a laptop doing an Illinois business name search

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.

Illinois Secretary of State (Contact)

Springfield office:

Limited Liability Division
501 S. Second St. Rm. 351
Springfield, IL 62756

Chicago office:

69 W. Washington St. Ste. 1240
Chicago, IL 60602

Springfield Phone: (217) 524-8008

Chicago Phone: (312) 793-3380

Hours: Monday–Friday, 8:00 a.m.–4:30 p.m. CT

Additional Steps

1. Trademark Search

When searching for a business name, it’s important to note that availability doesn’t necessarily mean the name is free to use if it’s already a registered trademark.

To avoid potential complications down the line, it’s wise to conduct a thorough trademark search using the Trademark Electronic Search System before finalizing a business name.

2. Choose a Registered Agent

After you have chosen an LLC name that is distinctive and unique, you can now choose your LLC’s Registered Agent.

3. Check if the Domain Name is Available

To check if a domain name is available, you can follow these steps:

  1. Go to a domain registrar website, such as or
  2. In the search bar on the homepage, type in the domain name you want to check.
  3. Click on the search button to see if the domain name is available or not.
  4. If the domain name is available, you will be prompted to purchase it. If it’s not available, the registrar will suggest some alternative options or you can try a different domain name.

4. Check if Social Media Name is Available

Check if a social media name is available for a new business name

5. Register Illinois Business Entity

When you complete the required documents for filing a new business entity, you then register your business and business name with the state. The state of Illinois will either approve your business name or reject it.

If you hire a good LLC service like Northwest Registered Agent, ZenBusiness or Incfile, these LLC services have business name tools available for you to do a quick search.

6. Register an Employer ID Number (EIN) With the IRS

An Employer Identification Number (EIN) is a unique nine-digit number assigned by the Internal Revenue Service (IRS) to identify businesses and other entities for tax purposes.

7. Create a Brand Logo

Creating a business logo involves several steps. There are affordable online services that can design a logo for you and assist with the process.

Define your brand: Before you start creating a logo, you need to define your brand’s personality, values, and mission. This will help you create a logo that accurately represents your brand.

8. Write a Business Plan

Writing a business plan involves a comprehensive process that covers various aspects of your business, including the industry, market research, marketing and sales strategies, financial projections, and more.

9. Open a Business Bank Account in Illinois

A bank account is generally required for a new Limited Liability Company (LLC) or corporation to separate personal finances from business finances and to establish a clear record of business transactions.

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)
author avatar
Brian Wilson Writer and Editor
Brian Wilson is the content manager and founder of LLC Radar. Brian grew up in North Texas, just outside of Dallas, and has a bachelor's degree in business from Southern Methodist University. Since graduating from SMU, Brian has gained over 10 years of experience in business writing for several online publications. Brian resides in Plano, Texas and he can be reached by email: Phone: 972-776-4050
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