Illinois Certificate of Formation: What It Really Is (2026)
Illinois does not use a "certificate of formation." To create an Illinois LLC you file Articles of Organization (Form LLC-5.5) with the Illinois Secretary of State for a $150 fee. "Certificate of formation" is the term used in states such as Delaware, Texas, and Washington - in Illinois, the Articles of Organization are the equivalent document.
Quick Answer
- Illinois LLC document
- Articles of Organization, Form LLC-5.5
- "Certificate of formation"
- Not an Illinois term - used in DE, TX, WA, NJ, NH
- Filing fee
- $150 (2026); series LLC (LLC-5.5(S)) is $400
- Agency
- Illinois Secretary of State - Department of Business Services
- Corporation instead?
- Articles of Incorporation, not a certificate
- Certificate Illinois does issue
- Certificate of Good Standing (for a fee)
Does Illinois Have a "Certificate of Formation"?
No. If you are searching for an "Illinois certificate of formation," you are looking for the document that legally creates a business, but Illinois calls that document something else. Under the Illinois Limited Liability Company Act (805 ILCS 180), an LLC is formed by filing Articles of Organization - the Secretary of State's Form LLC-5.5 - not a certificate of formation. The confusion is understandable: different states use different names for the same filing, and legal templates often say "certificate of formation" because they were written for Delaware or Texas.
The practical answer is simple. To start an Illinois LLC, file Form LLC-5.5 with the Illinois Secretary of State, Department of Business Services, and pay the $150 fee. For the complete walkthrough, see how to form an LLC in Illinois, and for the document itself, see Illinois Articles of Organization.
The Illinois Equivalent: Articles of Organization
The Articles of Organization are the charter document for an Illinois LLC. Filing them - and the Secretary of State's acceptance - is the legal act that brings the LLC into existence under Section 5-5 of the LLC Act. Whatever a form-provider or another state calls it, in Illinois the operative document is Form LLC-5.5. A corporation, by contrast, files Articles of Incorporation under the Business Corporation Act - again, not a "certificate."
Here is how the vocabulary lines up across common states so you can translate a template:
| State | LLC formation document |
|---|---|
| Illinois | Articles of Organization (Form LLC-5.5) |
| Delaware | Certificate of Formation |
| Texas | Certificate of Formation (Form 205) |
| Washington | Certificate of Formation |
| Ohio | Articles of Organization (Form 610) |
| Massachusetts / Connecticut | Certificate of Organization |
So an Illinois filer using a Delaware-style checklist should read "certificate of formation" as "Articles of Organization (Form LLC-5.5)." Compare the document across states on our Articles of Organization overview and the Ohio guide.
Why the Terminology Differs Across States
There is no national LLC statute. Each state wrote its own limited liability company act, usually building on one of two model laws - the Uniform Limited Liability Company Act or the older Prototype LLC Act - and each legislature picked its own label for the formation document. States that followed the Delaware model tend to say "certificate of formation." States that borrowed the older "articles" vocabulary used for corporations tend to say "articles of organization." Illinois is in the second group: its LLC Act uses "Articles of Organization" to parallel the "Articles of Incorporation" that corporations file.
The label does not change what the document does. Whether a state calls it a certificate of formation, a certificate of organization, or articles of organization, it is the public filing that creates the entity, names the registered agent, and starts the entity's legal life. Problems arise only when a template written for one state is used verbatim in another: a founder in Illinois who signs a "Certificate of Formation" downloaded for Delaware has not formed anything in Illinois, because the Illinois Secretary of State only accepts its own Form LLC-5.5. If you are working from a generic operating agreement or formation checklist, translate every "certificate of formation" reference to "Articles of Organization" before you rely on it. When in doubt, start from the Secretary of State's own form rather than a third-party template.
What the Illinois Articles of Organization Require
Form LLC-5.5 asks for the same core facts a certificate of formation would in another state:
- LLC name with a required designator ("LLC," "L.L.C.," or "Limited Liability Company"), distinguishable from existing names.
- Principal place of business address.
- Registered agent and registered office in Illinois - see Illinois registered agent requirements.
- Purpose - a general lawful-business statement is accepted for most LLCs.
- Management - member-managed or manager-managed, with the managers or managing members named.
- Organizer name and signature.
- Effective date, which may be delayed up to 60 days.
Internal ownership terms live in your operating agreement, which Illinois does not file. That mirrors how a certificate of formation works in other states: the public document is minimal, and the detailed governance is private.
How to File and What It Costs
You file Form LLC-5.5 with the Illinois Secretary of State online through the Department of Business Services, or by mailing the paper form with a check. Online filing is fastest. The fees below are set by Section 50-10 of the LLC Act and are effective for 2026. For the full cost of forming and running the LLC, see Illinois LLC cost.
| Filing | Form | Fee (2026) |
|---|---|---|
| Articles of Organization (standard LLC) | LLC-5.5 | $150 |
| Articles of Organization (series LLC) | LLC-5.5(S) | $400 |
| Application to reserve a name (90 days) | LLC-1.15 | $25 |
| Articles of Amendment | LLC-5.25 | $50 |
| Annual report (each year) | LLC-50.1 | $75 |
Before filing, run an Illinois business entity search to confirm the name is available, and clear it against federal trademarks. Expedited processing is available for an additional fee; confirm the current amount with the Secretary of State.
Which Illinois "Certificates" Do Exist
Illinois does issue documents with "certificate" in the name - just not for formation. The two you are most likely to need are:
- Certificate of Good Standing. Certifies that an existing LLC or corporation is on record and current on its annual reports and fees. Banks, lenders, and other states often require it. You order it from the Department of Business Services for a fee.
- Certified copy. An official, stamped copy of your filed Articles of Organization or other documents, ordered from the Secretary of State for a fee.
Note the difference: a formation document creates the entity, while a Certificate of Good Standing confirms an existing entity is current. If someone asks your Illinois LLC for a "certificate of formation," they usually want either the stamped Articles of Organization or a Certificate of Good Standing - clarify which, then provide the right one.
A common scenario is registering your Illinois LLC to do business in another state (foreign qualification). That state will typically ask for a recent Illinois Certificate of Good Standing to prove your LLC is validly formed and current - not a "certificate of formation." Lenders and landlords ask for the same document at closing. Order it close to when you need it, because these certificates are dated and some recipients will not accept one that is more than 30 to 90 days old. If your LLC is not currently in good standing because of a missed annual report, you must file the delinquent annual report and pay the $75 fee plus any $100 penalty before the state will issue the certificate.
Registered Agent and Ongoing Duties
However it is named, forming the LLC triggers ongoing duties. Section 1-35 of the LLC Act requires every Illinois LLC to continuously maintain a registered agent and registered office in Illinois; you name them on Form LLC-5.5 and update them with a $25 statement of change if they move. Each year the LLC files the annual report (Form LLC-50.1) with a $75 fee, due before the first day of its anniversary month. Miss it and Illinois assesses a $100 penalty and can administratively dissolve the LLC. See Illinois registered agent and Illinois annual report.
After You File
Once the Secretary of State accepts the Articles of Organization, finish setting up the LLC: apply for a free federal EIN from the IRS (a single-member LLC is a disregarded entity by default; a multi-member LLC is a partnership, and either can elect S-corporation status), adopt an operating agreement, and register for any Illinois taxes with the Department of Revenue using Form REG-1. See Illinois LLC tax filing and business licensing in Illinois.
Frequently Asked Questions
Does Illinois use a certificate of formation?
No. Illinois LLCs file Articles of Organization (Form LLC-5.5) with the Secretary of State for a $150 fee. "Certificate of formation" is used in states like Delaware, Texas, and Washington.
What is the Illinois equivalent of a certificate of formation?
The Articles of Organization, Form LLC-5.5, filed with the Illinois Secretary of State Department of Business Services. See Illinois Articles of Organization.
How much does it cost to form an LLC in Illinois?
$150 for a standard LLC and $400 for a series LLC. See Illinois LLC cost.
Is a certificate of formation the same as a certificate of good standing?
No. A formation document creates the entity; a Certificate of Good Standing (which Illinois issues for a fee) confirms an existing entity is current on its filings.
What document proves my Illinois LLC exists?
The stamped Articles of Organization returned by the Secretary of State. For third parties, order a Certificate of Good Standing.
Related
- Illinois Articles of Organization (Form LLC-5.5)
- How to form an LLC in Illinois
- Illinois business entity search
- Illinois registered agent requirements
- Illinois LLC cost and filing fees
- Illinois LLC annual report
- Articles of Organization (national overview)
- LLC vs corporation
- How to form an LLC (cluster hub)
Sources
- Illinois LLC Act - 805 ILCS 180/5-5, Articles of organization (formation document; contents).
- Illinois LLC Act - 805 ILCS 180/50-10, Fees ($150 Articles; $400 series; $50 amendment; $75 annual report).
- Illinois LLC Act - 805 ILCS 180/1-10, Limited liability company name.
- Illinois LLC Act - 805 ILCS 180/1-35, Registered office and registered agent.
- Illinois LLC Act - 805 ILCS 180/50-1, Annual report.
- Illinois Business Corporation Act - 805 ILCS 5 (Articles of Incorporation for corporations).
- Illinois Secretary of State - Limited Liability Companies (Department of Business Services).
- Illinois Secretary of State - Corporations (Articles of Incorporation).
- Illinois Secretary of State - Business Services home (online filing; certificates).
- Illinois Department of Revenue - Business Registration (Form REG-1).
- IRS - Limited Liability Company (LLC) (federal default classification).
- IRS - Get an Employer Identification Number (free EIN).
- 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 terminology change; verify current requirements with the Illinois Secretary of State before acting.