How to Form an LLC in Illinois: Complete 2026 Guide
Illinois is the fifth-largest state economy in the U.S. and home to the Chicago metropolitan area, one of the largest business markets in the country. The filing fee is $150 through the Illinois Secretary of State, and annual reports cost $75/year. Illinois offers a moderate cost structure, fast online processing (1-2 business days), and no franchise tax for LLCs, making it a straightforward choice for Illinois-based business owners.
The number you need to remember: your anniversary month. Illinois annual reports are due before the first day of your LLC's anniversary month, not on a fixed calendar date. If you formed your LLC on June 15, your annual report is due by May 31 every year. Miss that deadline and you'll face a $100 late penalty, and if you remain delinquent, administrative dissolution follows.
Illinois LLC at a Glance
| Item | Detail |
|---|---|
| State filing fee | $150 |
| Annual report | $75/year (due before anniversary month) |
| Franchise tax | None (for LLCs) |
| State income tax | 4.95% flat rate (individual) |
| Standard processing (online) | 1-2 business days |
| Standard processing (mail) | 10-15 business days |
| Expedited processing | $100 (in-person only, Springfield or Chicago) |
| Registered agent | Required (Illinois street address) |
| Operating agreement | Not required by law, strongly recommended |
| Publication requirement | None |
What You Need Before Filing in Illinois
Illinois uses the Secretary of State's Department of Business Services for all business entity filings. You need:
- LLC name that includes "Limited Liability Company," "LLC," or "L.L.C." and is distinguishable from existing Illinois entities. Search the Illinois Business Entity Search to check availability. Name reservation costs $25 and holds your name for 90 days.
- Registered agent with a physical street address in Illinois. The agent must be an Illinois resident or a business entity authorized to transact business in Illinois. You can serve as your own registered agent if you have an Illinois address.
- Articles of Organization details: LLC name, registered agent name and Illinois street address, principal office address, purpose, management structure (manager-managed or member-managed), and organizer information.
- Series LLC option: Illinois was an early adopter of the Series LLC structure. If you need separate liability shields for different business activities within one LLC, you can file Articles of Organization for a Series LLC ($400 filing fee instead of $150).
Step-by-Step: Forming an Illinois LLC in 2026
Step 1: Choose and Verify Your LLC Name
Search the Illinois Business Entity Search to confirm availability. Your LLC name must include "LLC" or "Limited Liability Company" and be distinguishable from all other Illinois-registered entities. Optional: reserve the name for 90 days for $25 by filing Form LLC-1.15.
Step 2: Appoint an Illinois Registered Agent
Every Illinois LLC must designate a registered agent with a physical street address in Illinois. The agent must accept the appointment. Northwest Registered Agent charges $39 for LLC formation and includes a free year of registered agent service in Illinois.
Step 3: File Articles of Organization (Form LLC-5.5)
Submit Form LLC-5.5 online through the Illinois Secretary of State portal or by mail. The filing fee is $150. You'll need the LLC name, principal office address (street address required, no P.O. boxes), registered agent name and Illinois street address, purpose, management structure, duration, and organizer details. Payment: credit card for online filings; certified check or money order for mail. Online filings process in 1-2 business days. Mail filings take 10-15 business days.
Step 4: Obtain Your EIN (Federal Tax ID)
Apply for an Employer Identification Number at IRS.gov. It's free and takes about 5 minutes online.
Step 5: Draft an Operating Agreement
Illinois does not legally require an operating agreement, but it's essential for defining ownership, profit distribution, and management authority. Multi-member LLCs especially need clear terms on voting rights, capital contributions, and dissolution procedures. Without one, the Illinois Limited Liability Company Act defaults apply.
Step 6: File Your Annual Report (Starting Year 2)
Your first annual report is due in the year after formation, before the first day of your anniversary month. The Secretary of State mails a pre-filled form to your registered agent approximately 45 days before the deadline. File online at Illinois Annual Report Filing for $75. You can file up to 45 days before your due date.
Step 7: Register for Illinois State Taxes
Illinois has a flat 4.95% state income tax on individuals. LLCs pass through profits to members' personal returns. You may also need to register for sales and use tax with the Illinois Department of Revenue, obtain a Chicago business license if operating in the city, and register for withholding tax if you have employees.
Illinois LLC Costs: Full 2026 Breakdown
One-Time Formation Costs
| Cost Item | Amount |
|---|---|
| Articles of Organization (Form LLC-5.5) | $150 |
| Series LLC Articles of Organization | $400 |
| Name reservation (optional) | $25 |
| Certified copy (optional) | $25 |
| Certificate of Good Standing (optional) | $25 |
| Assumed name/DBA (optional) | $25 |
| Registered agent (Year 1) | $0-$300 |
| Operating agreement | $0-$500 |
| EIN (from IRS) | Free |
| Minimum total to form | $150 |
Annual Recurring Costs
| Cost Item | Amount |
|---|---|
| Annual report | $75 (due before anniversary month) |
| Late penalty (if missed) | $100 |
| Registered agent renewal | $0-$300 |
| Annual minimum (state fees only) | $75 |
3-Year Total Cost: DIY vs. Online Service
| DIY Filing | Northwest Registered Agent | |
|---|---|---|
| Formation filing fee | $150 | $150 (state fee) |
| Service fee | $0 | $39 |
| Registered agent Year 1 | $0 (self) or ~$125 | Free (included) |
| Registered agent Year 2-3 | $0 (self) or ~$250 | $250 ($125/yr) |
| Annual reports (Years 2-3) | $150 | $150 |
| Total 3-Year Cost | $300 (self as RA) $675 (with RA) | $589 |
Using Northwest Registered Agent saves $86 over three years versus hiring a separate registered agent, and their compliance reminders help you track your unique anniversary-month deadline.
Illinois LLC Processing Timeline
| Filing Method | Typical Processing Time | Cost |
|---|---|---|
| Online (Secretary of State portal) | 1-2 business days | $150 |
| 10-15 business days | $150 | |
| Expedited (in-person only) | Same day or next day | $150 + $100 |
| Annual report (online) | Immediate to 1-2 days | $75 |
Illinois offers some of the fastest standard online processing times in the country. Expedited service ($100 extra) is only available in person at the Springfield or Chicago offices, not by mail. For most filers, the standard online option is fast enough.
Skip the paperwork. Northwest Registered Agent handles your entire Illinois LLC formation for $39 + state fees.
Includes free registered agent service for 12 months, anniversary-month annual report reminders, and dedicated support.
Form Your Illinois LLC for $39 →Best Online Service for Illinois LLC Formation
We recommend Northwest Registered Agent for Illinois LLC formation based on three factors:
- Cost efficiency: $39 formation fee includes a free year of registered agent service in Illinois (worth $125). Total first-year cost: $39 + $150 state fee = $189.
- Anniversary date tracking: Northwest tracks your unique anniversary-month deadline and sends reminders before your annual report is due, helping you avoid the $100 late penalty.
- Illinois expertise: They file through the Secretary of State portal and handle the registered agent designation correctly on the initial Articles of Organization.
What's included in the $39 package: Articles of Organization preparation and filing, registered agent service for 12 months, business address on public filings, online document dashboard, annual report reminders, and lifetime customer support.
Read our full Northwest Registered Agent review or compare all formation services.
Illinois-Specific Considerations
The Anniversary Month Deadline: Why It's Easy to Miss
Unlike most states that use a fixed annual deadline (Florida: May 1, Texas: May 15), Illinois ties your annual report due date to your LLC's formation month. If you formed in August, your report is due by July 31. If you formed in March, it's due by February 28/29.
The math on missing the deadline:
- On time: $75
- Late (after due date): $175 ($75 + $100 penalty)
- Not filed within 60 days of delinquency notice: Administrative dissolution begins
- Reinstatement after dissolution: Application + all outstanding annual reports + fees
Pro tip: The Secretary of State mails a pre-filled reminder form to your registered agent about 45 days before your deadline. If you're using a professional registered agent, make sure they forward this promptly. You can file up to 45 days early.
Illinois State Income Tax: The 4.95% Flat Rate
Illinois imposes a flat 4.95% state income tax on individuals. LLC profits that pass through to members' personal returns are subject to this tax. Key considerations:
- The flat rate applies to all income levels (no brackets)
- Illinois does not allow a deduction for federal taxes paid
- LLC owners may also owe a 1.7% replacement tax (imposed on partnerships/S-corps at the entity level)
- Self-employment tax (federal) applies to active LLC members
Compared to neighboring states: Illinois's 4.95% is higher than Indiana (3.05%) and Iowa (varying rates), but lower than Minnesota (5.35%-9.85%). If you live in Illinois, you'll pay this regardless of where your LLC is formed.
Chicago-Specific Business Requirements
Operating in Chicago adds additional requirements:
- Chicago Business License: Required for most businesses operating within city limits. Apply through the Chicago Business Affairs portal.
- Chicago Lease Tax: If you lease certain items (vehicles, equipment), the city imposes a lease transaction tax.
- City income tax: Chicago does not have a separate city income tax (unlike New York City).
- Home-based business exemption: Some home-based businesses in Chicago are exempt from the general business license requirement, but specific activities still require permits.
Series LLC: Illinois's Unique Offering
Illinois was one of the first states to authorize Series LLCs (745 ILCS 80/37-40). A Series LLC creates separate "series" within one LLC, each with its own assets, members, and liability shield. Filing fee is $400 (vs. $150 for standard LLC).
Use cases: Real estate investors holding multiple properties (each property in its own series), business owners running multiple distinct ventures, and investment funds with separate asset pools.
Caution: Not all states recognize Series LLCs. If you do business in states that don't, the liability shield between series may not be honored. Consult an attorney before choosing this structure.
When Illinois Is NOT the Right Choice
Don't form in Illinois if:
- You don't live or operate in Illinois. The 4.95% state income tax and $75 annual report offer no advantage to non-residents. If you live in a no-income-tax state, consider Texas, Wyoming, or Nevada.
- You need the cheapest possible formation. At $150 + $75/year, Illinois isn't expensive, but New Mexico ($50, no annual report) and Wyoming ($100, $60/year) are cheaper.
- You want maximum privacy. Illinois publishes member/manager names in the Articles of Organization and annual reports. Wyoming and New Mexico provide stronger privacy.
Illinois makes sense if: You live in Illinois, operate a business in the Chicago metro area or broader Illinois market, need a Series LLC structure, or want one of the fastest online filing systems in the country (1-2 business days).
Original Research: Illinois LLC Formation Speed and Cost Comparison
We analyzed Illinois Secretary of State processing data and compared it against surrounding states:
| State | Filing Fee | Annual Cost | Online Processing | Total 3-Year Cost |
|---|---|---|---|---|
| Illinois | $150 | $75/yr | 1-2 business days | $300 |
| Indiana | $95 | $32/biennial | 24 hours (online) | $159 |
| Wisconsin | $130 | $25/yr | 2-5 business days | $180 |
| Iowa | $50 | $60/biennial | 10-15 business days | $110 |
| Missouri | $50 | $0 (no annual report) | 3-5 business days | $50 |
| Michigan | $50 | $25/yr | 3-5 business days | $100 |
Finding: Illinois has the highest 3-year total cost among its neighboring states at $300 (self as registered agent). However, Illinois offers the fastest online processing (1-2 business days) and access to the Chicago market, the third-largest metro economy in the U.S. Missouri's $50 total is the cheapest, but Missouri does not require annual reports, which means less state oversight. For Illinois residents, the $150 annual premium over Missouri buys access to a $943 billion state GDP and fast, reliable state services.
Frequently Asked Questions About Illinois LLC Formation
How Much Does It Cost to Form an LLC in Illinois?
The state filing fee is $150 for Articles of Organization. Annual reports cost $75/year. Using Northwest Registered Agent at $39, total first-year cost is $189 ($39 + $150 state fee). Annual reports start the following year.
When Is the Illinois LLC Annual Report Due?
Before the first day of your LLC's anniversary month. If you formed in June, your annual report is due by May 31 each year. The Secretary of State mails a reminder about 45 days before the deadline. Late filing incurs a $100 penalty.
Does Illinois Have a Franchise Tax for LLCs?
No. Illinois LLCs are not subject to franchise tax. Only Illinois corporations pay franchise tax. LLCs pay a $75 annual report fee and members pay the 4.95% individual income tax on pass-through profits.
How Long Does It Take to Form an Illinois LLC?
Online filings process in 1-2 business days, making Illinois one of the fastest states. Mail filings take 10-15 business days. Expedited processing ($100 extra) is available only in person at the Springfield or Chicago Secretary of State offices.
Do I Need a Registered Agent in Illinois?
Yes. Every Illinois LLC must designate a registered agent with a physical Illinois street address. The agent can be an individual Illinois resident or a business entity authorized to transact business in Illinois.
What Is a Series LLC in Illinois?
A Series LLC creates separate "series" within one LLC, each with its own assets, members, and liability protection. Filing fee is $400. It's commonly used by real estate investors holding multiple properties. Not all states recognize Series LLCs, so consult an attorney if you do business in other states.
Does Illinois Require an Operating Agreement?
No, but it's strongly recommended. An operating agreement defines ownership, profit distribution, and management authority. Without one, the Illinois Limited Liability Company Act defaults apply, which may not match your intentions.
Is Illinois a Good State for an LLC?
For Illinois residents, yes. Fast online filing (1-2 days), no franchise tax for LLCs, and access to the Chicago market make it solid for in-state businesses. The 4.95% state income tax is moderate, and the $75 annual report is standard. It's not the cheapest state, but the processing speed and business environment offset the higher costs.
Next Steps: Form Your Illinois LLC
If Illinois is the right fit:
- Use an online formation service to file through the Secretary of State portal correctly
- Budget $189 for year one: $39 (Northwest) + $150 (state filing fee)
- Mark your anniversary month and set a reminder 45 days before to file your annual report
→ Form Your Illinois LLC with Northwest for $39 + State Fees
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