Form a Business in Illinois
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Everything you need to form and maintain an LLC, Corporation, S-Corp, or DBA in Illinois. Filing fees, ongoing requirements, and tax treatment current for 2026 — sourced from the Illinois Secretary of State and the IRS.
Illinois business formation overview
If you're forming a business in Illinois, the four most common entity types are the LLC (most popular for solo founders and small partnerships), the C-Corporation (used by venture-funded startups), the S-Corporation (a tax election available to LLCs and corporations meeting IRS rules), and the DBA ("doing business as", a trade-name registration for sole proprietors and existing entities). Each has its own filing fee, ongoing report cycle, and tax treatment in Illinois.
The cheapest path to a registered business in Illinois is the LLC at $150 for the Articles of Organization. A C-Corporation costs $150 for the Articles of Incorporation, and a DBA registration is $5. After formation you'll have ongoing obligations: an annual report ($75, annual), a registered agent with a physical Illinois address, and any applicable franchise or income tax: Personal Property Replacement Tax 1.5%.
Illinois at a glance (2026)
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Frequently asked questions about forming a business in Illinois
How much does it cost to form an LLC in Illinois?
The state filing fee is $150 to file Articles of Organization with the Illinois Secretary of State. Optional add-ons (registered-agent service, expedited filing, certified copies) are extra. See our cost breakdown for the full picture.
Does Illinois require an annual report?
Yes — Illinois requires an annual report at $75 (annual). Missing the deadline triggers late fees and eventually administrative dissolution.
What is the franchise tax in Illinois?
Personal Property Replacement Tax 1.5% Always confirm rates with the Illinois Department of Revenue or your tax advisor before filing.
Do I need a registered agent in Illinois?
Yes. Every LLC and Corporation registered in Illinois must designate a registered agent with a physical street address in the state who can accept legal process during business hours. You can serve as your own agent, appoint a co-owner, or hire a commercial registered-agent service.
Sources & further reading
Disclaimer: Legal information, not legal advice. For advice about your specific situation, consult a licensed attorney or CPA in your state. See our full disclaimer.