How to Form an LLC in Illinois in 2026: A Step-by-Step Guide
Forming an LLC in Illinois protects your personal assets from business debts and lawsuits, gives your business a professional legal identity, and establishes the governance framework you’ll operate under from day one. This guide walks through every step of the process — from choosing your name to getting your EIN — so you can get your Illinois LLC formed correctly the first time.
Step 1: Choose Your LLC Name
Your LLC name must be distinguishable from every other registered business name in Illinois. It must also include a required designator: “Limited Liability Company,” “L.L.C.,” or “LLC.”
Before filing, verify name availability on the Illinois Secretary of State’s business name search. A name that’s available for LLC registration may still infringe a federally registered trademark — run a USPTO trademark search as well before committing to a name.
If you’re not ready to form but want to lock in the name, you can file a name reservation with the Illinois Secretary of State for 90 days.
Step 2: Appoint a Registered Agent
Every Illinois LLC must designate a registered agent — an individual or entity with an Illinois physical address who will receive legal documents (lawsuits, government notices) on behalf of the LLC.
Your options:
- You (if you have an Illinois street address — P.O. boxes are not allowed)
- A co-founder or employee with an Illinois address
- A professional registered agent service
Many founders use a professional service to keep their home address out of the public record and ensure uninterrupted coverage. Fitter Law’s General Counsel plan includes registered agent service.
Step 3: File the Articles of Organization
The Articles of Organization is the document that officially creates your LLC. You file it with the Illinois Secretary of State.
Required information:
- LLC name
- Principal place of business address (Illinois)
- Registered agent name and address
- Manager-managed vs. member-managed designation
- Duration (perpetual is standard)
- Names and addresses of organizers
Filing fee: $150 (as of 2026). Online filing via the Illinois Secretary of State website is faster and recommended over paper filing.
Processing time: Standard processing takes 10–15 business days. Expedited processing is available for an additional fee.
Step 4: Draft and Sign an Operating Agreement
Illinois law does not require LLCs to have a written operating agreement, but every LLC should have one — especially if there are multiple members.
An operating agreement governs:
- Ownership percentages and capital contributions
- Profit and loss allocations
- How decisions are made (voting rights, manager authority)
- What happens when a member wants to exit or transfer their interest
- Buy-sell provisions if a member dies, becomes disabled, or is expelled
- Dissolution procedures
Without an operating agreement, Illinois default rules apply — and they may not reflect what you and your co-founders actually intended. A well-drafted operating agreement from day one prevents disputes that become expensive later.
Fitter Law drafts LLC operating agreements for Illinois startups and reviews them on an ongoing basis as your company grows.
Step 5: Obtain Your EIN
An Employer Identification Number (EIN) is your business’s federal tax ID number, required to open a business bank account, hire employees, and file federal taxes. You obtain it from the IRS — it’s free and takes minutes to get online at IRS.gov.
Even single-member LLCs should have an EIN — using your Social Security Number for business purposes creates unnecessary identity theft exposure.
Step 6: Register for Illinois State Taxes
Depending on your business activities, you may need to register with the Illinois Department of Revenue for:
- Illinois Retailer’s Occupation Tax (sales tax) — if you sell taxable goods or services in Illinois
- Illinois withholding tax — if you have Illinois employees
- Illinois corporate income tax — LLCs taxed as corporations file the Illinois Corporate Income and Replacement Tax Return
Illinois LLCs also pay an annual LLC franchise tax of $75 per year (for most small businesses), due with the Annual Report.
Step 7: Open a Dedicated Business Bank Account
Maintaining a separate business bank account is one of the most important things you can do to preserve your limited liability protection. Courts look at whether the owner commingled personal and business funds when deciding whether to “pierce the corporate veil” and hold members personally liable for business debts.
Open a business checking account in the LLC’s name, using your EIN. Don’t pay personal expenses from the business account.
Step 8: Obtain Required Licenses and Permits
LLC formation gives your entity legal existence — it doesn’t automatically authorize you to operate in regulated industries. Depending on your business, you may also need:
- Illinois professional licenses (if you’re providing licensed services)
- City of Chicago or county business licenses
- Zoning permits for physical locations
- Industry-specific federal permits (food, firearms, financial services)
Annual Maintenance Requirements
Illinois LLCs must file an Annual Report with the Illinois Secretary of State each year. The filing window is the first day of the anniversary month of formation through the last day of that month. The fee is $75. Missing the filing deadline results in penalties and eventual administrative dissolution.
How Much Does It Cost to Form an LLC in Illinois?
| Item | Cost |
|---|---|
| Articles of Organization filing fee | $150 |
| Name reservation (optional) | $25 |
| Registered agent service (professional) | $50–$300/year |
| Operating agreement (attorney-drafted) | Included in Fitter Law subscription |
| Annual Report fee | $75/year |
View Fitter Law’s subscription plans for bundled LLC formation and ongoing legal support — starting at $49.99/month.
Frequently Asked Questions
How long does it take to form an LLC in Illinois?
Online filing through the Illinois Secretary of State website typically processes in 5–10 business days. Expedited processing (for an additional fee) can reduce this to 24 hours. Attorney preparation of your Articles of Organization and operating agreement can be completed same-day for straightforward formations.
Do I need a lawyer to form an LLC in Illinois?
You’re not legally required to use an attorney. But the Articles of Organization is just the filing — the operating agreement and the strategic decisions that go with it (entity type, ownership structure, member roles) benefit significantly from legal guidance. A $150 filing fee that results in an inadequate operating agreement can cost far more to fix later.
Can a single person form an LLC in Illinois?
Yes. Single-member LLCs are fully valid in Illinois. A single-member LLC provides liability protection and tax flexibility (it’s treated as a disregarded entity for federal tax purposes by default, simplifying your tax return). Even solo founders benefit from the LLC structure.