Illinois Business Entity Search: Free SOS Lookup (2026)
The Illinois business entity search is a free Illinois Secretary of State database that lets you look up any LLC or corporation on record by entity name, partial name, or file number. Use it to check whether a business name is available before you file, confirm an entity's status, and find its registered agent - at no charge through the Department of Business Services.
Quick Answer
- Tool
- Business Entity Search (Corporation / LLC database)
- Agency
- Illinois Secretary of State - Department of Business Services
- Cost
- Free to search online
- Search by
- Entity name, partial name, or file number
- Shows
- Status, entity type, formation date, registered agent, annual report month
- Official document
- Certificate of Good Standing available for a fee
What the Illinois Business Entity Search Is
The Illinois business entity search is the public lookup for the Illinois Secretary of State, Department of Business Services corporation and LLC database. Every domestic and foreign LLC, corporation, limited partnership, and not-for-profit registered in Illinois appears in this database. The search is free and available online, so anyone can verify an Illinois business without creating an account or paying a fee.
The database is the same source the state uses when it reviews your Articles of Organization for name availability. That is why founders use it first: it tells you whether the name you want is already taken before you spend the $150 filing fee. For the full formation process, see how to form an LLC in Illinois.
How to Use the Illinois Business Entity Search
Searching takes a minute:
- Open the search. Go to the Illinois Secretary of State Department of Business Services and open the business entity (Corporation/LLC) search.
- Choose a search type. Select search by entity name, by a partial or "starting with" name, or by file number.
- Enter your term. Type the exact name, a keyword, or the file number and submit.
- Open a result. Click a matching entity to view its detail record - status, type, formation date, registered agent, and more.
Because Illinois requires a name to be distinguishable from existing names, search variations, not just the exact phrase. Try singular and plural forms, drop or add "the," and test abbreviations. If several close matches already exist, expect the Secretary of State to reject a name that is not distinguishable from them. Note that adding an entity designator alone - turning "Riverside Bakery" into "Riverside Bakery LLC" - usually does not make a name distinguishable from an existing "Riverside Bakery Inc.," because the designator is disregarded when the state compares names. Punctuation and spacing differences are treated the same way.
The search runs in real time against the live database, so results reflect entities that have been processed. A filing submitted minutes earlier may not yet appear, which is one reason a name that looks open can still be rejected. If two founders happen to file similar names close together, the earlier accepted filing wins. Doing your search immediately before you file - rather than weeks ahead - reduces the chance that someone claims the name in the gap.
What Information the Search Shows
Each entity's detail record generally displays:
| Field | What it tells you |
|---|---|
| Entity name | The exact legal name on file |
| File number | The unique ID the Secretary of State assigns to the entity |
| Entity type | LLC, corporation, series LLC, not-for-profit, and so on |
| Status | Active, dissolved, revoked, or not in good standing |
| Formation / registration date | When the entity was organized or qualified in Illinois |
| Registered agent & office | The current agent name and Illinois address |
| Annual report month | The anniversary month the annual report is due |
The record does not list the members or owners of an LLC. Illinois LLCs are not required to publish ownership in the state database, so the search tells you who the agent is and whether the entity is active, but not who holds the interests.
Checking Name Availability Before You File
Name availability is the most common reason people run this search. Under Section 1-10 of the Illinois Limited Liability Company Act (805 ILCS 180), your LLC name must include an LLC designator and be distinguishable in the Secretary of State's records from existing and reserved names. The database is how you test that.
A clear search is a good sign, but it is not a guarantee - the Secretary of State makes the final call when you file, and a pending filing may not yet appear. If you want to lock a name in advance, file an Application to Reserve a Name (Form LLC-1.15) for a $25 fee, which holds the name for 90 days. And remember: availability in Illinois does not create trademark rights. Clear the name federally too before you build a brand. For the document you file once the name is clear, see Illinois certificate of formation.
Searching by File Number
Every registered Illinois entity has a file number - the identifier the Secretary of State assigns at registration. You use it on the annual report, the change of registered agent, and other filings. If you already know an entity's file number, searching by it goes straight to the correct record, which is faster than sifting through similar names. Keep your own LLC's file number with your formation records alongside the stamped Articles of Organization and your EIN.
Certificate of Good Standing and Copies
The free search shows status on screen, but banks, lenders, and other states often want an official Certificate of Good Standing (also called a Certificate of Existence). You order that separately from the Department of Business Services for a fee; it certifies that the entity exists and has met its annual report and franchise obligations. You can also order certified copies of an entity's filed documents. Because these fees are set in the LLC Act fee schedule and can change, confirm the current amount with the Secretary of State before ordering.
An entity that appears as "not in good standing" usually has a missed annual report. To restore it, the LLC files the delinquent annual reports and pays the $75 fee plus any penalty; if it was administratively dissolved, it files for reinstatement.
Domestic, Foreign, and Assumed-Name Records
The database covers more than Illinois-formed LLCs. A domestic entity is one organized in Illinois; a foreign entity is one formed in another state that has registered to transact business in Illinois. Both appear in the search, so a company headquartered in another state but operating in Illinois still shows up if it registered properly. If you are checking whether an out-of-state company is authorized to do business in Illinois, look for a foreign registration record in active status.
The search also surfaces assumed names (the Illinois version of a DBA). When an LLC or corporation adopts an assumed name under the Business Organizations statutes, that name is tied to the entity's record. This matters for name clearance: a name may be unavailable not because another LLC was formed under it, but because an existing entity adopted it as an assumed name. When you search a prospective name, note any assumed names that match, and see Illinois DBA filing for how assumed names are registered. Corporations that used to hold a name but later dissolved may free it up, but a recently dissolved name can still be protected for a period, so treat close matches cautiously.
What the Search Cannot Tell You
The database is authoritative on registration, but it has limits. It does not show LLC ownership, it does not confirm that a business holds required licenses or tax registrations, and it does not tell you whether a name infringes a trademark. It also reflects only what has been processed; a very recent filing may not appear yet. For tax accounts, you register separately with the Illinois Department of Revenue - see Illinois LLC tax filing.
Common Uses of the Search
Beyond name clearance, the Illinois business entity search is used to:
- Vet a vendor or partner by confirming the company is a real, active Illinois entity and identifying its registered agent for service of process.
- Locate a registered agent when you need to serve legal papers on a company.
- Confirm your own status before a bank or contract closing that requires good standing.
- Check a name across entity types - including corporations and assumed names - not just LLCs.
Frequently Asked Questions
Is the Illinois business entity search free?
Yes. Searching the Secretary of State database is free. Only official documents such as a Certificate of Good Standing or certified copies carry a fee.
How do I search for a business in Illinois?
Open the Department of Business Services business entity search, choose to search by name, partial name, or file number, enter your term, and open the matching record.
What does the Illinois business entity search show?
The entity name, file number, type, status, formation date, registered agent and office, and the annual report month. It does not show LLC ownership.
How do I check if a business name is available in Illinois?
Search the exact and similar names. If nothing on record is indistinguishable from yours under 805 ILCS 180/1-10, the name is likely available, subject to the Secretary of State's decision when you file. See Articles of Organization.
What is an Illinois file number?
The unique identifier the Secretary of State assigns each registered entity. You use it on the annual report and other filings, and you can search directly by it.
Related
- Illinois Articles of Organization (Form LLC-5.5)
- How to form an LLC in Illinois
- Illinois certificate of formation explained
- Illinois registered agent requirements
- Illinois LLC annual report
- Illinois DBA (assumed name) filing
- Illinois LLC cost
- How to trademark a business name
- How to form an LLC (cluster hub)
Sources
- Illinois Secretary of State - Business Entity Search (Corporation/LLC database).
- Illinois Secretary of State - Department of Business Services home.
- Illinois Secretary of State - Limited Liability Companies.
- Illinois Secretary of State - LLC Annual Report (file number; status).
- Illinois LLC Act - 805 ILCS 180/1-10, Limited liability company name (distinguishability standard).
- Illinois LLC Act - 805 ILCS 180/1-15, Reserved name (90-day reservation).
- Illinois LLC Act - 805 ILCS 180/50-10, Fees (certificate and copy fees; $25 name reservation; $75 annual report).
- Illinois LLC Act - 805 ILCS 180/50-1, Annual report (anniversary month).
- Illinois LLC Act - 805 ILCS 180/1-35, Registered office and registered agent.
- Illinois Department of Revenue - Business Registration (Form REG-1).
- IRS - Get an Employer Identification Number (free EIN).
- IRS - Limited Liability Company (LLC).
- Cornell Law LII - Limited liability company (LLC) (legal definition).
LegalGlass provides general information for educational purposes and is not a law firm or a substitute for advice from a licensed attorney or tax professional. Laws, fees, and database features change; verify current requirements with the Illinois Secretary of State before acting.