Place1
Number one hereMainstay Filing
1. Mainstay Filing: best for one price in every state
$199 + state fee; agent renews at $149
Our mark9.5out of 10
Top of our list: Mainstay Filing, for it prepares and files the Illinois registration for $199 and names itself your registered agent, free for year one.
From year two the agent costs $149 a year, the same in every state.
Over three years it costs $100 more than Illinois Registered Agent.co, and we think the extra coverage earns that here.
What you get
- Registration prepared and filed
- Your registered agent, free for the first year
- Service of process scanned the same business day, no fee
Why pick it
- Service of process scanned the same business day, no fee
- Same price in all fifty states
- Registered agent free for the first year
- $199 + the Illinois fee
Less good
- $149 agent renewal, $50 above Illinois Registered Agent.co
Place2
Best value hereIllinois Registered Agent.co
2. Illinois Registered Agent.co: best for Illinois registration on a budget
$199 + state fee; agent renews at $99
Our mark9.0out of 10
Number 2 is Illinois Registered Agent.co: Illinois registration at $199 plus state fees, agent included for year one.
It provides the in-state registered office address and posts scans of served legal papers online.
What you get
- Foreign registration done for you
- A year of registered agent service
Why pick it
- Then $99 a year
- Service fee $199
- A year of registered agent service included
Less good
- Covers Illinois only
- $99 extra for the EIN application
Place3
Best value hereIL Registered Agent.org
3. IL Registered Agent.org: best for a local Illinois filer
$199 + state fee; agent renews at $99
Our mark8.7out of 10
Third: IL Registered Agent.org, for Illinois registration at $199 plus state fees, agent included for year one.
It provides the in-state registered office address and posts scans of served legal papers online.
Same prices and features as Illinois Registered Agent.co; pick whichever you prefer.
What you get
- Foreign registration done for you
- A year of registered agent service
Why pick it
- Service fee $199
- A year of registered agent service included
- Then $99 a year
Less good
- Covers Illinois only
- $99 extra for the EIN application
Quick comparison: Illinois
| Rank | Service | Our score | Service fee | Year two | Best for | Link |
|---|
| 1 | Mainstay Filing | 9.5 | $199 | $149/yr | Companies registered in several states | Visit Mainstay FilingPartner link. We may earn money if you buy. |
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| 2 | Illinois Registered Agent.co | 9.0 | $199 | $99/yr | Lowest agent renewal on this list | Visit Illinois Registered Agent.coPartner link. We may earn money if you buy. |
|---|
| 3 | IL Registered Agent.org | 8.7 | $199 | $99/yr | Lowest agent renewal on this list | Visit IL Registered Agent.orgPartner link. We may earn money if you buy. |
|---|
Each score is our editorial judgment out of 10 (see How we rank), not an average of customer ratings.
Illinois pricing for 2026: what each service costs
| Service | Year one | Year two | Year three | Three-year total | Agent in year one |
|---|
| Mainstay Filing | $199 | $149 | $149 | $497 | Free |
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| Illinois Registered Agent.co | $199 | $99 | $99 | $397 | Included |
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| IL Registered Agent.org | $199 | $99 | $99 | $397 | Included |
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Prices from each company's own pricing pages, read November 12, 2026. These totals leave out Illinois's $150 registration fee.
Why this order
Our method scores three-year cost (30%) and what one price covers (30%) most heavily, then renewal terms, fit for the state and price clarity. Here the order came down to what one price covers.
Multi-state companies need agents in each state, and one price everywhere outscored Illinois Registered Agent.co.
See How we rank for every criterion and weight.
How foreign registration works in Illinois
A company formed in another state registers with the Illinois Secretary of State, Department of Business Services, Limited Liability Division by filing the Application for Admission to Transact Business (Form LLC-45.5). The state fee is $150. Illinois also wants certificate of Good Standing or Existence, dated within 60 days.
After registering, the company files the annual report ($75), due within the 60 days before your anniversary month.
Your checklist
- Certificate of Good Standing or Existence, issued no more than 60 days before you file.
- The company's home-state name and formation date.
- An in-state registered agent, which each ranked service provides.
- The $150 state fee, paid with the filing.
- A date in your calendar for the annual report and its $75 fee.
If you never register
Without registering, it cannot file suit in Illinois (805 ILCS 180/45-45(a)). Its contracts stay valid (805 ILCS 180/45-45(b)). Back fees for the time it operated without registering are due as well.
Common Illinois questions
Do I need to register my out-of-state LLC in Illinois?
Yes, if the company transacts business there. Until it registers it cannot bring a lawsuit in the state's courts.
How much does foreign registration cost in Illinois?
The state fee is $150. The services we rank add $199 to prepare and file it.
Which form does the state use?
The Application for Admission to Transact Business (Form LLC-45.5), filed with the Illinois Secretary of State, Department of Business Services, Limited Liability Division.
Do I need a certificate from my home state?
Yes: certificate of Good Standing or Existence, dated within 60 days of filing.
Do I need a registered agent after registering?
Yes. Every LLC must name a registered agent with an in-state street address.
Which foreign registration service is best in Illinois?
We rank Mainstay Filing first for $199 over the state fee, the first registered agent year included, then $149 a year.
Official sources and price pages
- Illinois Secretary of State, Department of Business Services, Limited Liability Division (checked August 2026): www.ilsos.gov/departments/business-services/annual-reports/llc-instruc
- Illinois Secretary of State, Department of Business Services, Limited Liability Division (checked August 2026): www.ilsos.gov/departments/business-services/annual-reports.html
- 805 ILCS 180/5-5 (checked August 2026): www.ilga.gov/legislation/ilcs/fulltext.asp?DocName=080501800K5-5
- Illinois formation fee: Filing fee, official source (checked October 2026): www.ilga.gov/legislation/ilcs/fulltext.asp?DocName=080501800K50-10
- Illinois formation fee: Filing fee, official source (checked October 2026): www.ilsos.gov/publications/business-services/llc.html
- Illinois registered agent statute (checked October 2026): www.ilga.gov/legislation/ilcs/fulltext.asp?DocName=080501800K1-35
- Form LLC-45.5, Application for Admission (checked October 2026): www.ilsos.gov/content/dam/publications/pdf_publications/llc455.pdf
- Form LLC-45.40, Application for Withdrawal (checked October 2026): www.ilsos.gov/content/dam/publications/pdf_publications/llc4540.pdf
- 805 ILCS 180/45-45, consequences of transacting business without admission (checked October 2026): www.ilga.gov/legislation/ilcs/fulltext.asp?DocName=080501800K45-45
- 805 ILCS 180/45-47, activities that are not transacting business (checked October 2026): www.ilga.gov/legislation/ilcs/fulltext.asp?DocName=080501800K45-47
- 805 ILCS 180/45-45 (checked November 2026): ilga.gov/legislation/ilcs/documents/080501800K45-45.htm
- Mainstay Filing: Illinois service page, read November 12, 2026
- Illinois Registered Agent.co: pricing and service pages, read November 12, 2026
- IL Registered Agent.org: pricing and service pages, read November 12, 2026