Key Takeaways
- Search tool: Business Entity Search, free, run by the Illinois Secretary of State — Department of Business Services
- Search by business name and, for some record types, officer or registered agent information
- Name reservation available for $25 (90 days)
- Illinois lists LLC members/owners in the public record
- New LLC names must include a designator such as "Limited Liability Company," "L.L.C.," or "LLC"
- Same-day name-availability confirmation and formation filing available through LLC Attorney at no markup on state fees
Searching for an Illinois business name is free and fast, but the real complexity shows up after the search — Illinois splits its DBA system by entity type, and sole proprietors face a mandatory newspaper publication requirement that catches many first-time filers off guard.
This guide covers exactly how to search for an Illinois business or check LLC name availability in 2026 — the Business Entity Search, Illinois's distinguishable-name standard, name reservation, the newspaper publication trap for DBAs, and what a search actually reveals, including full member and manager disclosure.
How to Search for a Business in Illinois
Use the Illinois Secretary of State — Department of Business Services's Business Entity Search to search for an existing business or check whether a new LLC name is available. Search by business name and, for some record types, officer or registered agent information. The search is free.
Search directly at apps.ilsos.gov/businessentitysearch.
Review every result carefully, including inactive and dissolved entities — a dissolved entity's name may retain residual protection for a period, so a name that looks free at first glance can still be blocked. Illinois's $150 filing fee makes a careful pre-check especially worthwhile before you submit Articles of Organization.
Results show entity status, registered agent, and filing history. Because Illinois requires full member or manager disclosure on every annual report, a detail page often reveals more ownership information than in privacy-friendlier peer states.
Checking Name Availability Before You File
Use the same Business Entity Search to check for conflicts before filing. Given Illinois's $150 Articles of Organization fee, a thorough manual review of every close match — including dissolved entities — is worth the extra few minutes before you submit.
Illinois's Distinguishability Standard
805 ILCS 180/1-10 (the LLC Act) and the parallel Business Corporation Act require names be "distinguishable" upon Secretary of State records. Critically, a name is not made distinguishable merely by adding "limited," "liability," "company," or their abbreviations — Illinois looks past the designator to the substantive core of the name. Final confirmation only happens at filing.
Reserving a Name in Illinois Before You Form
Name reservation available: For $25, you can reserve your chosen name for 90 days before filing.
File Form LLC-1.15 for $25 to hold your name for 90 days. The reservation is non-renewable — once it expires, you must file a brand-new $25 reservation rather than extending the existing one — and the fee is not credited toward your $150 Articles of Organization filing fee.
Searching for DBAs and Fictitious Names in Illinois
Illinois runs a split DBA system by entity type. LLCs, corporations, LLPs, and LPs register a statewide Assumed Business Name with the Secretary of State for $150 for a 5-year term (prorated if shorter). Sole proprietors and general partnerships instead file with the county clerk ($25–$50 depending on county, e.g., Cook County charges $50) — and critically, must also publish notice in a local newspaper once weekly for 3 consecutive weeks within 15 days of filing. This newspaper publication requirement is a genuine, easy-to-miss statutory holdover that trips up first-time filers.
Illinois LLC Naming Requirements
Your new LLC's name must include a designator such as "Limited Liability Company," "L.L.C.," or "LLC".
Restricted or regulated words require sign-off from the relevant state regulator before the Secretary of State will accept the filing, consistent with most states — this applies to both entity names and Assumed Business Names.
An Available LLC Name Isn't the Same as a Trademark-Safe Name
Illinois maintains its own Trademark/Servicemark registry through the Secretary of State (Form TM/SM-15), separate from entity name registration. It costs $10 per class, is searchable by mark, registration number, or registrant name, requires the mark to already be in commercial use (no intent-to-use filings like the USPTO allows), and lasts 5 years.
Illinois's Business Entity Search and its state trademark registry only cover Illinois-registered names and marks. Search the USPTO's Trademark Electronic Search System (TESS) separately before committing to a name, especially since Illinois's state registry requires actual use and won't reveal pending federal applications.
What a Illinois Business Search Reveals
Illinois has strict transparency requirements: the annual report must list the names and addresses of all managers (in a manager-managed LLC) or all members with manager-level authority (in a member-managed LLC) — this information cannot be omitted or filed confidentially. Illinois does not permit anonymous LLCs.
Illinois lists LLC members/owners in the public record, so a search can reveal ownership information.
Getting a Illinois Certificate of Good Standing
You can confirm an LLC's good standing status and request a Certificate of Good Standing through the same Business Entity Search, for $25 standard / $45 for 24-hour expedited processing (instant online purchase and print for standard, or 24 hours for expedited).
How to Search and Reserve Your Illinois LLC Name
If You Do It Yourself
Step 1 — Search the Business Entity Search at apps.ilsos.gov/businessentitysearch.
Search by business name and, for some record types, officer or registered agent information to confirm your desired name isn't already taken.
Step 2 — Apply the state's distinguishability standard, not just an exact-match check.
805 ILCS 180/1-10 (the LLC Act) and the parallel Business Corporation Act require names be "distinguishable" upon Secretary of State records. Critically, a name is not made distinguishable merely by adding "limited," "liability," "company," or their abbreviations — Illinois looks past the designator to the substantive core of the name. Final confirmation only happens at filing.
Step 3 — Check your name against restricted/regulated words.
Restricted or regulated words require sign-off from the relevant state regulator before the Secretary of State will accept the filing, consistent with most states — this applies to both entity names and Assumed Business Names.
Step 4 — Confirm your name includes a required LLC designator.
Your name must include a designator such as "Limited Liability Company," "L.L.C.," or "LLC".
Step 5 — Reserve your name for $25 if you're not ready to file yet.
File Form LLC-1.15 for $25 to hold your name for 90 days. The reservation is non-renewable — once it expires, you must file a brand-new $25 reservation rather than extending the existing one — and the fee is not credited toward your $150 Articles of Organization filing fee.
Step 6 — Run a separate USPTO trademark search before you commit.
Illinois's Business Entity Search and its state trademark registry only cover Illinois-registered names and marks. Search the USPTO's Trademark Electronic Search System (TESS) separately before committing to a name, especially since Illinois's state registry requires actual use and won't reveal pending federal applications.
Step 7 — File your formation documents promptly once you've confirmed availability.
If you didn't reserve the name, nothing holds it for you — another filer could take it first.
Step 8 — Watch for Illinois-specific search quirks.
The single biggest Illinois-specific trap is the mandatory newspaper publication requirement for sole-proprietor and general-partnership DBAs — a holdover statutory requirement many people simply don't expect to still exist in 2026, and missing the 3-consecutive-week window within 15 days of filing can create real compliance headaches. Illinois's strict "no confidential member filings" stance is also notable, since it contrasts sharply with neighboring Indiana, which makes member disclosure entirely optional.
If LLC Attorney Does It for You
- Submit your desired business name at llcattorney.com along with one or two backup options.
- LLC Attorney runs the Illinois name-availability search, checks it against restricted-word rules, and confirms your designator is correctly formatted before filing.
- Receive confirmation once your name is filed, plus access to flat-fee attorney consultations (no retainer) if a trademark conflict or distinguishability question comes up.
When Should You Talk to an Attorney About Your Illinois LLC Name?
Talk to an attorney before finalizing an Illinois LLC name if you're operating as a sole proprietorship or general partnership and need to understand the newspaper publication requirement for your county, if a close name variant already appears in your industry and you're unsure whether it's distinguishable enough, or if you want full trademark clearance beyond Illinois's own use-based state registry.
Is Illinois a State Where Name Clearance Complexity Matters More?
Illinois is one of the more complex states in this guide to search correctly because entity-type filings and DBA filings run through completely different systems and levels of government — the Secretary of State for entity names and statewide Assumed Business Names, versus the county clerk (plus mandatory newspaper publication) for sole-proprietor and partnership DBAs. Confirming what applies to your specific business structure before you search is the first step, not an afterthought.
What You Actually Get With LLC Attorney's Illinois Name Search
Illinois's DBA rules split by entity type, and the newspaper publication requirement for sole proprietors is easy to miss until it's too late. LLC Attorney flags exactly which path applies to your business as part of every formation order.
- A Illinois name-availability search run for you before you pay any state filing fee.
- Restricted-word and distinguishability screening, so your filing isn't rejected for a naming issue you didn't know about.
- Formation starting at $49, with your confirmed name filed the same day where the state allows it.
- Access to professionally trained Business Success Advisors at no charge, plus flat-fee attorney consultations (no retainer) for trademark-conflict questions.
Illinois requires full member disclosure with no anonymity option — LLC Attorney makes sure you understand exactly what will be public before you file, not after.
Ready to Form Your Illinois LLC?
Once you've confirmed your name is available, LLC Attorney can handle the rest of your Illinois LLC formation, starting at $49. See our full pricing for all service tiers.
Frequently Asked Questions
Yes. Illinois's Business Entity Search is completely free to use, checked live against Secretary of State records.
Search the Business Entity Search for your proposed name and review every close match, including dissolved entities. 805 ILCS 180/1-10 requires names be distinguishable on Secretary of State records — adding "LLC" or similar designators alone does not make an otherwise-conflicting name distinguishable. Final confirmation happens only at filing.
Yes. File Form LLC-1.15 for $25 to hold your name for 90 days. The reservation is non-renewable, so if it lapses you'll need to file a new $25 reservation, and the fee doesn't count toward your $150 Articles of Organization fee.
Yes — Illinois requires full disclosure. The annual report must list all managers (manager-managed) or all members with manager-level authority (member-managed), and this cannot be filed confidentially. Illinois does not offer an anonymous LLC option.
You can obtain a Certificate of Good Standing for $25 with instant online purchase and printing, or pay $45 for 24-hour expedited processing.
It depends on your entity type. LLCs, corporations, LLPs, and LPs register a statewide Assumed Business Name with the Secretary of State for $150 (5-year term). Sole proprietors and general partnerships instead file with the county clerk and must also publish notice in a local newspaper once weekly for 3 consecutive weeks — an easy-to-miss requirement.
Your Illinois LLC name must include "Limited Liability Company," "L.L.C.," or "LLC" and must be distinguishable from other names on the Secretary of State's records — simply adding a designator to an otherwise-conflicting name doesn't clear it. Regulated terms require separate licensing approval.
No. Illinois's Business Entity Search and its own state Trademark/Servicemark registry only check Illinois records, and the state registry requires actual commercial use rather than covering pending applications. Search the USPTO's TESS database separately for federal trademark conflicts.
Yes. LLC Attorney runs a Illinois name-availability search as part of every formation order, and flags any restricted-word or distinguishability issue before you pay a filing fee.