How to Start an LLC in Illinois (2026): 7 Steps and the 3 Best LLC Services
Lesson answer for Illinois in 2026: if you want help with starting an LLC, use Illinois Registered Agent.co ($199), IL Registered Agent.org ($199) and Mainstay Filing ($199), in that order. Below the picks you will find 7 steps in order, starting with the name and ending with the yearly upkeep (filing fee $150).
Each company's listed price on November 12, 2026. Plus the $150 state fee in each case.
Step-by-step lesson
Step1
Step 1: Choose a name and check it is free
Your first homework: search the state's business records for the name you want. The Illinois Secretary of State keeps that list.
TipCheck the matching web domain at the same time.
Step2
Step 2: Name a registered agent
Every LLC must name a registered agent with an in-state street address. An Illinois resident, or a business authorized to do business in Illinois. The LLC cannot act as its own agent.
The address has to be a registered office in Illinois that matches the agent's business office. A P.O. box alone is not accepted.
TipEach pick above can serve as the registered agent.
Official source: As listed on ilga.gov in October 2026
Step3
Step 3: File it yourself, or hire it out
Doing it yourself costs $150. Using one of our picks adds $199, and the agent comes with it.
Step4
Step 4: File the Articles of Organization
This filing creates the company: the Articles of Organization (Form LLC-5.5), $150, sent to the Illinois Secretary of State.
Official source: As listed on ilsos.gov in October 2026
Step5
Step 5: Get the company's tax ID (EIN)
Wait for the state's approval, then get the EIN from the IRS. You need it to open accounts in the LLC's name. If you use Mainstay Filing, the EIN application is included.
Step6
Step 6: Agree the house rules in writing
Put ownership and decision rules into an operating agreement and keep it with the company papers.
Step7
Step 7: Plan for year two and beyond
After year one the main job is the Limited Liability Company Annual Report ($75, every year, by before the first day of the entity's anniversary month). The penalty for filing late is $100.
Official source: As listed on ilsos.gov in October 2026
Illinois costs by step
Step
Who you pay
Amount
Filing the LLC
State office
$150
Limited Liability Company Annual Report
State office
$75 every year
Missing the deadline
State office
$100
Filing service (optional)
Service
$199 to start
State fees, years one to three
State office
$300
The state rows are official figures; the service row uses each company's published price. The three-year total leaves service fees out.
How the grade worked out
The grade turned on three-year cost (30%), where Illinois Registered Agent.co came out ahead of IL Registered Agent.org.
Three years of Illinois Registered Agent.co cost $397, which leaves $200 in your pocket compared with Mainstay Filing.
Quick answers
What does it cost to form an LLC in Illinois?
$150 to the state. Add $199 if a service files it.
Which form creates the LLC?
You submit the Articles of Organization (Form LLC-5.5) to the Illinois Secretary of State.
Is a registered agent required?
Every LLC must name a registered agent with an in-state street address.
What does Illinois require each year?
The Limited Liability Company Annual Report: $75, every year, due before the first day of the entity's anniversary month.
Can I form the LLC without a service?
Yes, file it yourself ($150) and appoint a registered agent.
Which LLC service should a first-time founder use?
In order: Illinois Registered Agent.co, IL Registered Agent.org and Mainstay Filing. Illinois Registered Agent.co comes first because formation at $199 over the state fee, then a $99 agent renewal.