How to Form LLC in Illinois

Quick Answer

Forming an LLC in Illinois requires filing Articles of Organization with the Illinois Secretary of State for a $150 filing fee. As of April 10, 2026, processing takes 5-10 business days. You’ll need a registered agent with an Illinois address and a unique business name that complies with state requirements.

Step-by-Step Formation Process

1. Choose Your LLC Name: Verify your desired name is available through the Illinois Secretary of State’s business entity search. Your name must include “Limited Liability Company,” “LLC,” or “L.L.C.” and cannot be identical to existing entities.

2. Designate a Registered Agent: Appoint a registered agent with a physical Illinois address who can receive legal documents during business hours. This can be yourself, another person, or a professional service.

3. File Articles of Organization: Complete and submit Form LLC-5.5 (Articles of Organization) to the Illinois Secretary of State. You can file online through the Illinois Secretary of State website at https://www.ilsos.gov/departments/business_services/ or by mail.

4. Pay the Filing Fee: Submit the $150 formation fee with your Articles of Organization. Online filings typically process faster than mail submissions.

5. Obtain an EIN: Apply for an Employer Identification Number (EIN) from the IRS, even if you don’t plan to have employees. This is free directly from the IRS website.

6. Create an Operating Agreement: While not required by Illinois law, draft an operating agreement to establish management structure, profit distribution, and member responsibilities.

7. Open a Business Bank Account: Use your filed Articles of Organization and EIN to open a dedicated business bank account to maintain the corporate veil.

Costs Breakdown

Fee Type	Amount	Description
Articles of Organization	$150	Required state filing fee
Annual Report	$75	Due annually to maintain good standing
Name Reservation (Optional)	Contact Secretary of State	To reserve name before filing
Registered Agent Service (Optional)	$100-300/year	If using professional service
Operating Agreement (Optional)	$200-1,000	Attorney fees if professionally drafted

Fees current as of April 10, 2026. Contact the Illinois Secretary of State for the most current fee schedule.

Requirements Checklist

Before filing your Illinois LLC, ensure you have:

• Unique Business Name: Verified availability and includes required LLC designation
• Registered Agent: Individual or entity with Illinois physical address
• Articles of Organization: Completed Form LLC-5.5 with all required information
• Filing Fee: $150 payment ready for submission
• Principal Office Address: Physical address for your LLC’s main location
• Member Information: Names and addresses of initial members
• Management Structure: Decision on member-managed vs. manager-managed structure

Tax Implications

Illinois LLCs face several tax considerations as of April 10, 2026:

State Income Tax: Illinois imposes a 4.95% flat income tax rate on LLC profits passed through to members. Unlike some states, Illinois does not offer tax-free LLC status.

Federal Tax Treatment: By default, single-member LLCs are taxed as sole proprietorships, while multi-member LLCs are taxed as partnerships. You can elect corporate tax treatment by filing Form 8832 with the IRS.

Self-Employment Tax: LLC members typically pay self-employment tax (15.3%) on their share of LLC profits, covering Social Security and Medicare contributions.

Sales Tax: If your LLC sells taxable goods or services, you’ll need to register for Illinois sales tax. The base state sales tax rate is 6.25%, with additional local taxes possible.

No Franchise Tax: Illinois does not impose a franchise tax on LLCs, unlike some states that charge annual franchise taxes based on income or net worth.

Ongoing Obligations

Illinois LLCs must meet several ongoing compliance requirements:

Annual Reports: File an Annual Report with the Illinois Secretary of State and pay the $75 annual fee. This maintains your LLC’s good standing and updates state records with current information.

Tax Filings: File annual tax returns with both the IRS and Illinois Department of Revenue. Multi-member LLCs file Form 1065 federally and Form IL-1065 with Illinois.

Registered Agent Maintenance: Ensure your registered agent remains available at the designated Illinois address. Notify the Secretary of State of any registered agent changes.

Record Keeping: Maintain corporate records including operating agreement, member resolutions, financial statements, and tax returns. While Illinois doesn’t specify retention periods, keeping records for at least seven years is recommended.

Business License Renewals: Renew any required business licenses or permits according to their specific schedules, which vary by industry and locality.

Registered Agent

Illinois law requires every LLC to maintain a registered agent with a physical address in the state. The registered agent receives legal documents, official notices, and service of process on behalf of your LLC during normal business hours.

Registered Agent Options:

• Yourself: You can serve as your own registered agent if you have an Illinois address and are available during business hours
• Another Person: A friend, family member, or business associate with an Illinois address can serve
• Professional Service: Registered agent companies provide reliable service and privacy protection

Registered Agent Responsibilities:

• Maintain a physical Illinois address (not a P.O. Box)
• Be available during normal business hours Monday through Friday
• Receive and forward legal documents promptly
• Notify you immediately of any official correspondence

Changing Registered Agents: You can change your registered agent by filing the appropriate form with the Illinois Secretary of State and paying any required fees.

Common Mistakes to Avoid

1. Choosing an Unavailable Name: Always search the Illinois Secretary of State database before settling on a name. Similar names may cause rejection or legal issues later.

2. Using a P.O. Box for Registered Agent: Illinois requires a physical street address for your registered agent. P.O. Boxes are not acceptable.

3. Skipping the Operating Agreement: While not legally required, an operating agreement protects your limited liability status and prevents disputes between members.

4. Mixing Personal and Business Finances: Always maintain separate bank accounts and financial records to preserve your LLC’s limited liability protection.

5. Ignoring Annual Report Deadlines: Missing your Annual Report filing can result in administrative dissolution of your LLC and loss of good standing.

6. Inadequate Record Keeping: Poor documentation can pierce the corporate veil and expose members to personal liability.

7. Forgetting to Obtain Required Licenses: Research and obtain all necessary business licenses and permits for your specific industry and location.

Related Guides

• How to Form Corporation in Illinois: 2026 Step-by-Step Guide
• How to Form LLC in Arkansas: 2026 Step-by-Step Guide
• How to Form LLC in Connecticut: 2026 Step-by-Step Guide
• How to Form LLC in Hawaii: 2026 Step-by-Step Guide
• How to Form LLC in Kentucky: 2026 Step-by-Step Guide

Frequently Asked Questions

How long does it take to form an LLC in Illinois?

As of April 10, 2026, the Illinois Secretary of State processes LLC formations in 5-10 business days for standard filings. Expedited processing may be available for an additional fee, though you should contact the Secretary of State for current expedited options and costs.

Do I need an operating agreement for my Illinois LLC?

While Illinois law does not require an operating agreement, creating one is strongly recommended. An operating agreement establishes management structure, member responsibilities, profit distribution, and procedures for adding or removing members. This document helps maintain your limited liability protection and prevents disputes.

Can I be my own registered agent in Illinois?

Yes, you can serve as your own registered agent if you have a physical address in Illinois and are available during normal business hours Monday through Friday. However, many business owners prefer professional registered agent services for privacy and reliability.

What happens if I don’t file my Annual Report?

Failing to file your Annual Report and pay the $75 fee will result in your LLC falling out of good standing with the state. Continued non-compliance can lead to administrative dissolution, loss of limited liability protection, and potential penalties.

How much does it cost to maintain an Illinois LLC annually?

The minimum annual cost is $75 for the required Annual Report fee. Additional costs may include registered agent services ($100-300), business licenses, tax preparation, and any professional services you require.

Can a non-resident form an Illinois LLC?

Yes, non-Illinois residents can form an LLC in the state. However, you must still maintain a registered agent with a physical Illinois address and comply with all state requirements.

Do I need to publish my LLC formation in Illinois?

No, Illinois does not require LLC publication in newspapers, unlike some states such as New York. This saves significant costs compared to states with publication requirements.

What business licenses might my Illinois LLC need?

License requirements vary by business type and location. Common licenses include general business licenses from your city or county, professional licenses for regulated industries, and sales tax permits if selling taxable goods or services. Research requirements specific to your business and location.

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This article provides general information for educational purposes only and should not be considered legal or tax advice. Consult with an attorney or accountant for guidance specific to your situation. Information current as of April 10, 2026.