Look up any Illinois business by name or file number to verify its status and agent, and also know how to check if your chosen LLC or corporation name is free to claim.
About to sign a contract or wire a deposit to a company you found online? A 30-second search on the Illinois Secretary of State's site tells you if that business is real. You will see its current status, entity type, and registered agent.
The process is simple. All you need to do is type the business name into the state portal, and every matching entity appears. Select the right one from the list to check its information. Let's walk through it step by step, with real screenshots.
Key Takeaways
Illinois's Business Entity Search is a free, public tool from the Secretary of State. [1]
It allows you to search a company by its exact name, keyword, partial name, or file number to confirm a company's status, entity type, formation date, and registered agent.
The search is for information only. For certified proof that a business is active, you order a Certificate of Good Standing separately.
If you are naming a new business, you can reserve an available name for 90 days by filing Form LLC-1.15 (LLC) or Form BCA 4.10 (corporation). The hold cannot be renewed, so you must file your formation documents inside that window or start over.
What Is the Illinois Business Entity Search Tool
The Illinois Business Entity Search is a free, public lookup tool run by the Illinois Secretary of State’s Department of Business Services. Use it to confirm an entity’s file number, entity type, current status, date of incorporation or organization, and registered agent name and address. [1]
The tool covers every entity type Illinois allows people to form or register, including:
- Domestic and foreign corporations, including S corps electing at the federal level
- Not-for-profit corporations
- Limited liability companies (LLCs), including low-profit L3Cs
- Limited partnerships (LPs) and limited liability partnerships (LLPs)
General partnerships and sole proprietorships are not required to register with the Secretary of State, so they typically will not appear in this search. They instead register an assumed name at the county level, covered later in this guide.
How to Conduct an Illinois Business Entity Search
Step 1. Go to the Official Illinois Portal
Go directly to the Illinois Business Entity Search, the Secretary of State’s free official search tool. No account or login is required to run a basic search.
Step 2. Enter the Entity Name or File Number
Type the company’s exact name, a keyword from the name, or its file number if you already have it. A file-number search is faster and more precise because it avoids confusion caused by similarly named businesses.
If you only have a partial name, use the name or partial-word search options rather than common terms like "group" or "holdings," which return too many matches.
Step 3. Read Your Results
Once results load, you will see the entity’s legal name, file number, entity type, current status, date of incorporation or organization, and the name and address of the registered agent. This is the same information a Certificate of Good Standing formally certifies, just without the official seal. [1]
Note: A result showing "Active/Good Standing" is informational, not an official certificate. For certified proof, order a Certificate of Good Standing separately.
What the Illinois Business Search Does Not Show
The Illinois Business Entity Search does not display:
- Member, manager, or shareholder names, since these are not part of the searchable public record
- Financial records, revenue figures, or bank account information
- Assumed names (DBAs) registered at the county level by sole proprietors and general partnerships
- Real-time state tax standing beyond what is reflected in the entity’s status field
One Illinois-specific detail worth knowing:
Assumed names adopted by LLCs and corporations already registered with the Secretary of State do show up in the state system, since those are filed with ILSOS directly rather than at the county level. County-level assumed names apply only to sole proprietors and general partnerships operating under a trade name.
Checking Name Availability for a New Business
If you are forming a brand-new Illinois business rather than researching an existing one, search the same database yourself first, then file for an official name reservation if you want a binding hold before you submit formation paperwork.
How to Check Illinois Business Name Availability: Step-by-Step
Step 1. Search the Business Database Yourself
Run your desired name through the Illinois Business Entity Search described above. Look for exact matches and close variants. The Secretary of State makes the final call on whether two names are "distinguishable enough" to coexist.
Step 2. Apply Illinois’s Distinguishability Standard
Illinois law requires a proposed LLC or corporation name to be distinguishable from every other name already on file. LLC names may not borrow designators reserved for other entity types. Words like "Corporation," "Corp.," "Incorporated," "Ltd.," or "L.P." are off-limits for an LLC name, and vice versa.
Step 3. File an Application to Reserve a Name
For a binding hold before you file formation paperwork, submit an Application to Reserve a Name using Form LLC-1.15 for an LLC or Form BCA 4.10 for a corporation. Both reserve the name for 90 days.
Step 4. Note the 90-Day, No-Renewal Window
An Illinois name reservation lasts 90 days from filing, and neither the corporate nor LLC statute allows renewing it. If your 90 days lapse before you file your Articles of Organization or Incorporation, the name becomes available to anyone else. It means you would need to file and pay for a brand-new reservation. You can cancel an unused reservation early for $5, or transfer it to someone else for $25 (a transfer does not extend the 90-day clock).
Illinois’s Business Name Conventions
Illinois sets naming rules under the Limited Liability Company Act (805 ILCS 180) and the Business Corporation Act (805 ILCS 5). The core standard for every entity type is the same. The name must be distinguishable on the record from every other domestic or foreign entity already registered with the Secretary of State. [2]
Naming Rules for an Illinois LLC
Required designator: An Illinois LLC name must contain "LLC," "L.L.C.," or "Limited Liability Company." Low-profit LLCs must use "L3C" instead.
- Cannot use words reserved for other entity types, such as Corporation, Corp., Incorporated, Inc., Ltd., Co., or Limited Partnership/L.P.
- Cannot use "trust," "trustee," or "fiduciary" unless the LLC’s actual purpose involves managing trusts
- Permitted characters are English letters, Arabic numerals, and Roman numerals. Most other symbols need prior approval from the Department of Business Services.
Naming Rules for an Illinois Corporation
Required designator: An Illinois corporation name must include "corporation," "company," "incorporated," "limited," or a recognized abbreviation of one of those terms, and must be distinguishable from every other corporate name on file.
Illinois Business Entity Search Costs
Service | Fee | What You Need |
Business Entity Search | Free | Entity name, keyword, or file number |
LLC Name Reservation (90 days, Form LLC-1.15) | $25 | Proposed LLC name |
Corporation Name Reservation (90 days, Form BCA 4.10) | $25 | Proposed corporate name |
Cancel an unused name reservation | $5 | Reservation confirmation number |
Transfer a name reservation to another person | $25 | Reservation confirmation number |
24-hour expedited name reservation (in person only) | +$50 | In-person filing in Springfield/Chicago |
Certificate of Good Standing (LLC, corp, LP, LLP) | $25 standard / $45 expedited | Entity name or file number |
Certificate of Good Standing (nonprofit) | $5 standard / $15 expedited | Entity name or file number |
State-level Assumed Name filing (2026 rate) | $120 | Assumed name and entity file number |
A quirk worth knowing about the assumed name fee: Illinois prices state-level assumed name filings on a sliding scale tied to the calendar year, not a flat rate. [3]
- It is $150 in years ending in 0 or 5
- $120 in years ending in 1 or 6
- $90 in years ending in 2 or 7
- $60 in years ending in 3 or 8
- $30 in years ending in 4 or 9
So, the same filing costs less the closer it lands to the next renewal year
When to Consider an Assumed Name (DBA) in Illinois
If you plan to operate under a name different from your legal business name, Illinois splits the process by entity type:
- Registered LLCs, corporations, limited partnerships, and nonprofits file an assumed name directly with the Secretary of State, at the sliding-scale fee described above, and must renew it in the next year ending in 0 or 5 [3]
- Sole proprietorships and general partnerships register an assumed name with the county clerk in every county where they do business. The fees vary by county, from around $5 in some counties to $50 in Cook County [4].
County-level assumed names carry a publication requirement that state-level filings do not. You must publish a notice in a local newspaper once a week for three consecutive weeks, with the first notice within 15 days of filing, and file proof of publication with the county clerk within 50 days. [4].
Neither type of assumed name filing creates a new legal entity, and filing one does not by itself change your tax obligations.
Let Us File Your Illinois Business
Once your entity and name search is complete, the next step is filing your formation paperwork. Swyft Filings has helped more than 600,000 businesses get started since 2015. We can handle your Illinois LLC formation, registered agent service, and ongoing compliance so you do not have to track deadlines yourself. Let us handle your filing from name to formation.
Bibliography
- Illinois Secretary of State. Business Search / Certificate of Good Standing. Accessed on July 27, 2026.
- Illinois General Assembly. 805 ILCS 180/1-10, Limited Liability Company Name. Accessed on July 27, 2026.
- Illinois Secretary of State. Adopting an Assumed LLC Name (fee and renewal schedule). Accessed on July 27, 2026.
- Cook County Clerk's Office. Assumed Business Name Registration. Accessed on July 27, 2026.
Other Important Resources
- Illinois Business Portal. One-stop guide for registration, licensing, permits, etc
- Illinois Department of Revenue. Business Registration for state taxes.
- Illinois Department of Revenue. Income Tax Rates.
- Illinois Department of Professional and Financial Regulation. State-issued professional licenses for regulated industries.
- Illinois Department of Employment Security. Employer registration, unemployment insurance contributions, and more.
- SBA Illinois District Office, Chicago.
- IRS. EIN Online Application.
- USPTO. Trademark Portal.
