How to Form an LLC in Illinois (2026): Real Costs, Real Steps
Illinois LLC formation is mid-priced and process-light compared to California or New York: a single Articles of Organization filing, a registered agent, and a $75 annual report. The Illinois Secretary of State office processes online filings in about 10 business days. Illinois charges a 4.95% personal income tax, which matters for single-member LLCs whose profits flow through to the owner's individual return. This guide covers the Articles, the registered-agent rule, and the annual report.
Year-1 Cost Table
| Item | Cost | Source |
|---|---|---|
| Articles of Organization (Form LLC-5.5) | $150 | cite |
| Annual Report | $75/yr | cite |
| Registered agent (Northwest) | $125/yr | cite |
| Expedited 24-hour filing (optional) | $100 | cite |
| Year-1 total (standard) | $350 | cite |
The 6 Steps
- Step 1: File Articles of Organization
Submit the formation document to the Illinois Secretary of State. See the cost table above for the current filing fee.
- Step 2: Appoint a Registered Agent
Every Illinois LLC needs a registered agent with a Illinois street address. You can serve yourself, but most founders use a commercial RA — Northwest is our default pick.
- Step 3: Get an EIN (Federal Employer Identification Number)
Apply with the IRS using your stamped Articles of Organization. Free, takes 5 minutes online.
- Step 4: Adopt an Operating Agreement
Required by best practice — banks routinely request it before opening business accounts.
- Step 5: Open a Business Bank Account
Mercury for software/online businesses; a local credit union for cash-heavy retail. Keep personal and business finances separate from day one.
- Step 6: File State Tax Registrations
Register for Illinois state taxes (sales tax permit, payroll registration if you have employees, etc.) before you transact.
Recommended Tools
Northwest vs ZenBusiness for Illinois LLCs
Verdict (as of 2026): Northwest Registered Agent is our default pick for Illinois LLCs. They publish a Illinois-specific registered-agent page (linked in the cost table) and do not upsell add-ons at checkout. ZenBusiness wins only if you want bundled formation in a single flow.
| Criterion | Northwest | ZenBusiness |
|---|---|---|
| Registered-agent only price (Illinois) | $125/yr | $199/yr |
| Bundled formation | Optional add-on | Included in formation plans |
| Privacy (address shielding) | Strong | Strong |
| Upsells at checkout | None | Several |
| Annual-report filing service | $100/yr add-on | $199/yr add-on |
Frequently Asked Questions
How long does Illinois LLC formation take?
Standard online filings through the Illinois Secretary of State process in approximately 10 business days. Expedited 24-hour filings are $100 extra.
Does Illinois have a state income tax for LLCs?
Yes — Illinois imposes a 4.95% flat personal income tax, which applies to single-member LLC profits that flow through to the owner's individual return.
Can I be my own registered agent in Illinois?
Yes, if you have an Illinois street address (no P.O. boxes) and are available during business hours. Most founders use a commercial RA for privacy.
Does Illinois require an Operating Agreement?
Not legally required to be filed, but strongly recommended — banks and lenders typically request a copy before opening business accounts.
When is the Illinois LLC annual report due?
In the anniversary month of formation each year. There is a $100 late penalty after a 60-day grace period.
Annual Filing Deadline
Annual Report due in the LLC's anniversary month each year — $75