Foreign LLC Registration in Illinois (2026): 5 Moves and the 3 Best Services
Our 2026 marks for registering an LLC from another state in Illinois: IL Registered Agent.org ($199), Mainstay Filing ($199) and Illinois Registered Agent.co ($199), highest first. 5 moves and a $150 state fee; later reports cost $75 each.
From the Founder Primer desk
The short version
State fee to register
$150
Check it yourself at ilsos.gov; we read it in October 2026
Home certificate
60 days
Must be issued within
Report fee
$75
Annual report
Three-year state cost
$300
No service fees counted
Move count
5
Each one explained
After this primer
When registration is required
How the filing is made
What staying registered costs
Who we would hire to file
The Illinois shortlist
Five weighted criteria set the order (see how we score); three-year cost and to-dos cleared count most.
Best overall$199 to register, $99 a year after
1. IL Registered Agent.org: best for adding only Illinois
IL Registered Agent.org leads the list, since $199 plus state fees to register; the agent is paid through year one.
It beats Mainstay Filing on three-year cost, a big part of the score.
Inside the price
Filing with the state
One year of agent service
In its favor
Agent covered in year one
A $199 service fee
$99 a year for the agent after
Against it
Illinois only; your home state needs its own agent
Most work done for you$199 to register, $149 a year after
2. Mainstay Filing: best for LLCs expanding
Mainstay Filing takes second; $199 plus state fees to register, with the registered agent free for the first year.
Over three years it sits $100 behind IL Registered Agent.org.
Once the free year ends, expect $149 a year for the agent whichever state it covers.
Inside the price
Filing with the state
Registered agent free in year one
A fifty-state service
In its favor
$199 over Illinois's fee
One price anywhere
No agent fee in year one
Against it
Agent renews at $149, $50 above IL Registered Agent.org
Local option$199 to register, $99 a year after
3. Illinois Registered Agent.co: best for Illinois-only registrations
Third place is Illinois Registered Agent.co, because $199 plus state fees to register; the agent is paid through year one.
On price it ties with IL Registered Agent.org.
Inside the price
Filing with the state
One year of agent service
In its favor
$99 a year for the agent after
A $199 service fee
Agent covered in year one
Against it
Illinois only; your home state needs its own agent
Posted prices, read November 13, 2026. No row includes the $150 state fee.
The moves
Move 1
Does the rule reach your LLC?
If your out-of-state LLC does business in Illinois, register as a foreign LLC first. Operating unregistered costs you: A claim from an unregistered LLC will not go forward there (805 ILCS 180/45-45(a)). Signed contracts keep their force (805 ILCS 180/45-45(b)). Expect a bill for back fees.
Where this comes from: Check it yourself at ilga.gov; we read it in October 2026
Move 2
Request proof of good standing
Get certificate of Good Standing or Existence, dated within 60 days.
Order it when everything else is ready.
Move 3
Name the Illinois registered agent
Every LLC must name a registered agent with an in-state street address. 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.
Where this comes from: Check it yourself at ilga.gov; we read it in October 2026
Move 4
Send in the Application for Admission to Transact Business
the Illinois Secretary of State, Department of Business Services, Limited Liability Division takes the form and the $150 fee together.
Where this comes from: Check it yourself at ilsos.gov; we read it in October 2026
Move 5
Handle Illinois's repeating filing
Next up: the annual report, $75, within the 60 days before your anniversary month.
What each move costs in Illinois
Cost item
Pay to
Cost
Registering the LLC
To the state
$150
Annual report
To the state
$75
Filing service (optional)
Service
$199 to begin
Three-year state total
To the state
$300
These are the official Illinois fees, cited below. The three-year line adds the filing fee, the year-two and year-three reports and any minimum tax.
How the marks came out
Founder outlay over three years is 27% of the mark, and it is where moved ahead in Illinois.
IL Registered Agent.org takes the cost criterion: $397 over three years, against $100 more at Mainstay Filing.
Short answers
What does an LLC from elsewhere pay to register in Illinois?
$150 as the official fee. Add $199 if you hire a service.
Which form do I file to register?
Use the Application for Admission to Transact Business (Form LLC-45.5); the Illinois Secretary of State, Department of Business Services, Limited Liability Division receives it.
Do I need a certificate from my home state?
Yes: certificate of Good Standing or Existence, issued within 60 days of filing.
What if the LLC does business there without registering?
A claim from an unregistered LLC will not go forward there (805 ILCS 180/45-45(a)). Signed contracts keep their force (805 ILCS 180/45-45(b)). Expect a bill for back fees.
What is due after registering?
After registering, the LLC files the annual report; each one costs $75.
Which service should handle the registration?
IL Registered Agent.org, since $199 plus the state fee, first agent year included, then $99 a year. Then Mainstay Filing and Illinois Registered Agent.co.