Illinois Secretary of State filings, deadlines, and how to do them right.
Annual reports, business search, registered agent changes, reinstatement, dissolution, tax registration. Every Illinois filing explained, plus the business environment, regulatory bodies, and a year-round compliance calendar. Verified against the Illinois Secretary of State, Department of Business Services as of June 2026.
Why founders choose Illinois (and what to know first)
Chicago is the largest Midwest business hub. Major Fortune 500 concentration (Boeing, McDonald's, Caterpillar). Flat 4.95% income tax simplifies planning. Strong logistics infrastructure.
Tax obligations at a glance
Tax obligations depend on entity type, where you operate, and where revenue is sourced. Consult a licensed CPA for entity-specific advice. File.Business connects you with vetted CPAs in Illinois on request.
Other Illinois agencies your business will touch
The Secretary of State handles formation and corporate filings. These agencies handle the rest of your Illinois compliance.
State income tax, sales tax, withholding
Unemployment insurance
Insurance licensing
Workers comp
Professional licensing
Alcohol licensing
Year-round filings every Illinois business should know
Recurring federal and state deadlines that affect Illinois businesses. Our Compliance Calendar tracks these and 200+ others against your entity.
How to form an LLC in Illinois: step by step
Each step explained with what Illinois requires. File.Business handles all of this for $0 service fee plus the $150 state fee.
Search the state business name database to confirm the name is distinguishable. Must include LLC, L.L.C., or Limited Liability Company.
State street address required (no P.O. Box). The agent must accept the appointment and be available during business hours.
Submit to the Secretary of State with the state filing fee. Online filing is the fastest channel.
Not filed with the state but legally important. Defines members, contributions, distributions, and manager rules.
IRS Form SS-4. Online if a member has an SSN; mail/fax if all members are non-US.
Most banks require: Articles, EIN letter, operating agreement, and beneficial-owner ID.
Department of Revenue for sales tax, withholding accounts if hiring employees.
Ready to file your Illinois paperwork the easy way?
Five minutes per filing. State fee passed through at cost. Audit trail and deadline tracking included.
Disclosure. File.Business is a private business filing and compliance service. We are not a government agency and are not affiliated with the Illinois Secretary of State, Department of Business Services or any Secretary of State office. You may file directly with the Illinois Secretary of State, Department of Business Services. Information on this page is for general guidance only and is not legal, tax, or accounting advice. Filing fees and deadlines verified against the Illinois Secretary of State, Department of Business Services as of June 2026 and may change. For entity-specific guidance, consult a licensed Illinois attorney or CPA.
Every Illinois Secretary of State topic, in one place.
24 keyword-focused guides covering every filing, form, and compliance question for Illinois businesses.