Learn the steps to form an LLC in Illinois – from choosing your name to filing your Articles of Organization. $1 + $150 state fee. Start today.
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Filing fee: $150 (Articles of Organization) — same fee online or by mail
Processing time: 5-10 business days online; 3-4 weeks by mail
State agency: Illinois Secretary of State, Department of Business Services (ilsos.gov)
Annual report due: Before the first day of your LLC’s anniversary month each year — $75. File more than 60 days late and you owe a $100 penalty; at 180 days past due the state can dissolve your LLC.
State tax rate: Flat 4.95% income tax on pass-through income, plus a 1.5% entity-level replacement tax; 6.25% state sales tax; no franchise tax on LLCs and no general state business license
Start your U.S. business journey today. Form your company with confidence and let Brio handle the paperwork.
Forming an LLC in Illinois takes 5 steps: choose and check your business name, appoint a Registered Agent with a physical Illinois address, file Articles of Organization online or by mail, draft an operating agreement, and get an Employer Identification Number (EIN) from the IRS. The state filing fee is $150.
Illinois pairs the country’s fifth-largest economy with a simple flat tax: pass-through LLC income is taxed at 4.95% on your personal return, with no brackets to climb. LLCs also escape the Illinois franchise tax that corporations pay — the main entity-level cost is a modest 1.5% personal property replacement tax on net income. An LLC gives you personal liability protection and pass-through taxation without the administrative overhead of a corporation.
Forming here is also far cheaper than it used to be — the state cut the LLC filing fee from $500 to $150, though plenty of older articles still cite the old number. Ongoing paperwork is one $75 annual report, there’s no general state business license, and Illinois is one of the few states that offers the Series LLC structure if you plan to hold multiple ventures or properties under one umbrella.
Unlike some states, Illinois doesn’t require you to reserve your name before filing — you simply claim it when you file your Articles of Organization. If you’re not ready to file yet, you can optionally reserve a name with the Secretary of State. The fee is $25, and the reservation holds your name for 90 days (it can’t be renewed).
Your LLC name must be distinguishable from other registered businesses in Illinois and must include “Limited Liability Company,” “L.L.C.,” or “LLC.” Illinois is stricter than most states about what you can’t use: words like “Corporation,” “Corp.,” “Inc.,” “Ltd.,” “Co.,” or “L.P.” aren’t allowed in an LLC name. Check the Secretary of State’s business name database before you file to avoid a rejection.
Every Illinois LLC must have a registered agent — a person or entity designated to receive legal notices and government documents on behalf of the business. The agent must have a physical street address in Illinois (a P.O. box doesn’t count) and be available during regular business hours.
You can serve as your own registered agent if you have a physical Illinois address and can be there during business hours. Many business owners use a professional registered agent service instead — it keeps your personal address off public records and ensures someone is always available to receive documents.
The Articles of Organization (Form LLC-5.5) is the document that legally creates your Illinois LLC. You file it with the Secretary of State online at ilsos.gov or by mail. Online filing costs $150 and takes roughly 5-10 business days; mail filings take around 3-4 weeks including transit. If you’re in a hurry, 24-hour expedited service is available online or in person for an extra $100.
The Articles must include your LLC’s name, the principal place of business, your registered agent’s name and Illinois street address, and the names and addresses of the organizers or initial members/managers. If you’re forming a Series LLC, you file Form LLC-5.5(S) instead, and the fee is $400.
Illinois doesn’t require you to file an operating agreement with the state, but you should have one. It’s the internal document that defines how your LLC is managed — who owns what, how profits are distributed, and how decisions get made. Without one, the default rules of the Illinois Limited Liability Company Act fill in the gaps, which may not reflect what you actually want.
Your operating agreement should specify whether the LLC is member-managed or manager-managed. In a member-managed LLC, all owners share day-to-day authority. In a manager-managed LLC, a designated manager handles operations while other members retain economic rights. A written agreement is the version that holds up when disputes arise.
An Employer Identification Number (EIN) is a 9-digit federal tax ID issued by the IRS. Your Illinois LLC needs one to open a business bank account, hire employees, and file federal taxes. Applying online at irs.gov is free and issues your EIN immediately after you complete the application.
To use the IRS online application, the responsible party must have a valid Social Security Number (SSN) or Individual Taxpayer Identification Number (ITIN), and the business must have its principal place of business in the United States. The IRS does not charge a fee for issuing an EIN.
Illinois LLCs file one report with the Secretary of State: an annual report (Form LLC-50.1) due before the first day of your LLC’s anniversary month — the month it was formed. It costs $75, takes a few minutes online, and your first one is due the year after formation. There’s no initial report and no franchise tax on LLCs.
Two things catch Illinois LLC owners off guard. First, the annual report penalty: file more than 60 days late and a $100 penalty is added, and at 180 days past due the state administratively dissolves your LLC — reinstatement costs $200 plus back reports. Second, taxes: besides the 4.95% personal income tax, LLCs taxed as partnerships pay a 1.5% personal property replacement tax on net income, and if you sell taxable goods you must register with the Department of Revenue through MyTax Illinois (free) to collect the 6.25% state sales tax.
The required Illinois state fee is $150 to file the Articles of Organization with the Secretary of State — the same price online or by mail (a Series LLC costs $400). The annual report is $75, and reserving your name before filing is optional at $25. There’s no additional state fee to get your EIN; the IRS issues EINs for free.
Yes. Illinois allows a single person to form and own an LLC – this is called a single-member LLC. You can complete the Articles of Organization filing online at ilsos.gov without an attorney. You’ll still need to appoint a registered agent with a physical Illinois address, but that can be yourself if you qualify.
No. Illinois charges a $150 Articles of Organization fee – that’s a required state fee you can’t avoid. What you can avoid is paying extra for formation help. We handle your Illinois LLC filing for $1; you only pay the required state fees.
Yes. Every Illinois LLC files an annual report (Form LLC-50.1) with the Secretary of State, due before the first day of its anniversary month each year. The fee is $75. File more than 60 days late and a $100 penalty is added; once you’re 180 days past due, the state administratively dissolves your LLC, and reinstatement costs $200 plus all delinquent reports and penalties.
Yes, every Illinois LLC is required to have a registered agent. A registered agent is a person or entity that receives legal notices and official government documents on behalf of your LLC. The agent must have a physical street address in Illinois — not a P.O. box — and be available during regular business hours. You can serve as your own registered agent or use a professional service.
The mistakes that come up most often are missing the annual report because it’s tied to your anniversary month rather than a fixed calendar date — that triggers the $100 penalty and eventually dissolution — budgeting from outdated fee information (the old $500 filing fee and $300 penalty still circulate online), using a prohibited word like “Inc.” or “Co.” in the LLC name, and using a P.O. box for the registered agent address. A lot of owners also forget the 1.5% replacement tax, assuming “pass-through” means no entity-level Illinois tax at all.
Online filings at ilsos.gov are processed in roughly 5-10 business days. Mail filings take about 3-4 weeks including transit time. If speed matters, Illinois offers 24-hour expedited service for an extra $100 — but only online or in person at the Springfield or Chicago office; you can’t expedite a mailed filing.
Thinking about another state? Compare Wyoming, Delaware, Texas and Florida — or browse all 50 state guides.
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