How to Start an LLC in Illinois (2026)

To start an LLC in Illinois, you file Articles of Organization with the Illinois Secretary of State's Department of Business Services. The filing fee set by the Illinois Limited Liability Company Act is $150, and the Secretary of State offers expedited handling for an extra $100. After that, an Illinois LLC files an annual report each year before its anniversary month, for $75. This guide covers each step and links the official sources, chiefly the LLC Act itself (805 ILCS 180).

Check that your LLC name is available

The Secretary of State's Corporation/LLC entity database lets you look up existing companies and check whether a company name is available. Our Illinois business search guide explains what the search returns and how to read a File Detail Report.

The naming rules are in 805 ILCS 180/1-10. An Illinois LLC name:

• must contain "limited liability company," "L.L.C." or "LLC" (a low-profit LLC uses "L3C");
• may not contain "Corporation," "Corp.," "Incorporated," "Inc.," "Ltd.," "Co.," "Limited Partnership" or "L.P.";
• may use only English letters, Arabic or Roman numerals and symbols the Secretary of State can readily reproduce;
• may not use words restricted by another Illinois statute unless that restriction is met; for example, "trust," "trustee" and "fiduciary" require compliance with the Corporate Fiduciary Act; and
• must be distinguishable on the Secretary of State's records from other domestic and admitted foreign LLCs, reserved names, assumed names registered under the Act, and the names and assumed names of corporations.

If you are not ready to file, you can reserve a name. Under 805 ILCS 180/1-15, a reservation gives exclusive use of the name for 90 days, and the fee in 805 ILCS 180/50-10 is $25. The reservation is optional.

The Act also says that its name rules do not limit trademark or unfair competition law, so an accepted LLC name is not a trademark. Search the USPTO trademark database before you commit to a brand. For the general process, see how to check LLC name availability.

Appoint a registered agent

Under 805 ILCS 180/1-35, every Illinois LLC must continuously maintain a registered agent and registered office in Illinois. The agent must be an individual resident of Illinois or another person authorized to transact business in Illinois. The Act's definition of "person" includes corporations and LLCs, so a commercial registered agent company authorized in Illinois can serve. If an agent resigns, a new agent must be placed on record within 60 days, and failing to do so can put the LLC out of good standing. You can serve as your own agent if you live in Illinois. For background, see what a registered agent does.

File the Articles of Organization

Under 805 ILCS 180/5-5, Illinois articles of organization must set out:

1. the LLC's name and the address of its principal place of business, which does not have to be in Illinois;
2. its purposes, which may be stated as any lawful business an LLC may conduct;
3. the registered agent's name and the registered office address;
4. a confirmation that the LLC has at least one member at the time of filing, or will have one when the filing takes effect;
5. the name and business address of every manager and of any member who has a manager's authority;
6. its duration, which is perpetual unless stated otherwise; and
7. the name and address of each organizer.

Note item 5: unlike many states, Illinois puts managers, and members with management authority, on the public record. The LLC exists when the Secretary of State files the articles, or on a later date you specify of no more than 60 days after filing.

Fee. 805 ILCS 180/50-10 sets the fee for filing articles of organization at $150. An LLC formed with series, or with the ability to establish series, pays $400 instead.

Expedited filing. 805 ILCS 180/50-50 lets the Department of Business Services provide expedited service, meaning the filing is handled the same day or within 24 hours of the request. The expedited fee for articles of organization is $100, in addition to the $150 filing fee.

After your LLC is formed

Annual report ($75)

Illinois LLCs do not share one statewide deadline. Under 805 ILCS 180/50-1, the annual report and fees are due within the 60 days before the first day of the LLC's anniversary month, the calendar month in which its articles were filed. The first report is therefore due the year after formation. The report lists the registered agent and office, the principal place of business, and the managers and any members with a manager's authority. The filing fee is $75 under 50-10.

Missing the deadline is costly. Under 805 ILCS 180/50-15, an LLC that has not filed by the first day of its anniversary month is declared delinquent and not in good standing. If the default is not fixed before the first day of the second month after the anniversary month, the penalty is $100, plus $100 for each further year of delinquency. The Secretary of State can also administratively dissolve the LLC; our Illinois page covers dissolution and the $200 reinstatement filing.

EIN

Most LLCs need an Employer Identification Number for taxes, banking and hiring. The IRS issues EINs free; its online application issues the number immediately once approved. See what an EIN is.

Operating agreement

The operating agreement is not filed with the Secretary of State. Section 5-5 does allow the articles to include provisions about the LLC's internal affairs, but most owners keep those rules in a private written operating agreement covering ownership, management, profit sharing and what happens when a member leaves.

Assumed names, licenses and taxes

To do business under a name other than the LLC's legal name, Illinois LLCs file an application for an assumed name with the Secretary of State under section 1-20 of the Act; see DBA vs. LLC. Depending on your business and location, you may also need state tax registrations, professional licenses or local permits. The SBA's licenses and permits guide explains how federal, state and local requirements fit together.

Illinois LLC costs at a glance

The minimum state cost to form an Illinois LLC is the $150 filing fee, then $75 a year. These are the amounts the statute sets; check the Secretary of State's current forms when you file.

Do it yourself or use a formation service

You can form an Illinois LLC yourself. The articles ask for a short list of facts, and the only required cost is the $150 state fee, plus $100 if you want expedited handling. DIY works well if you live in Illinois and can act as registered agent, and you are comfortable tracking an annual report deadline that depends on your formation month.

A formation service adds its own fee on top of the state fees. In return it prepares and files the articles, can serve as your registered agent, and usually reminds you before the annual report window opens, which helps avoid Illinois's $100 late penalty. The state fees are the same either way.