Foreign registration ratings · Illinois
3 Best Foreign Registration Services in Illinois (2026)
1. Illinois Registered Agent.co: best for adding Illinois and nothing else
$199 for the service, plus state fees, then $99 a year for the agent
Illinois Registered Agent.co is rated first: $199 on top of the state fee to register in Illinois, agent at $99 afterward.
The plan lists an in-state street address as the registered office and scans papers served there into your account.
Its three-year sum is under Mainstay Filing's, which scores well on cost.
What you get
- Filing with the state
- A year of registered agent service at the start
Pros
- A $199 registration amount before the state fee
- The first registered agent year is covered
- Then $99 yearly for the agent
Trade-offs
- Illinois only; your home state needs its own agent
- EIN application billed at $99
2. Mainstay Filing: best for companies registered in more than one state
Service fee $199, with $349 due at checkout including the state fee; agent $149 a year after that
Mainstay Filing is rated second: $199 plus state fees in any state, first-year registered agent service included.
The agent line is $149 a year from year two, identical across states, after a free first year.
Illinois Registered Agent.co is $100 cheaper on the three-year sum, and that lowers Mainstay Filing's cost rating.
What you get
- Registration documents prepared and filed
- Year one as your registered agent, no charge
- Free scan-and-upload of papers served, the day they arrive
Pros
- $199 service fee, state fee separate
- Same-business-day scans of service of process, no fee
- The same amount in all fifty states
- Registered agent, no charge in year one
Trade-offs
- Agent renewal of $149 is $50 over Illinois Registered Agent.co
3. IL Registered Agent.org: best for Illinois registrations only
$199 for the service, plus state fees, then $99 a year for the agent
IL Registered Agent.org is rated third: $199 on top of the state fee to register in Illinois, agent at $99 afterward.
The plan lists an in-state street address as the registered office and scans papers served there into your account.
IL Registered Agent.org copies Illinois Registered Agent.co on amounts and plan features, so there is little between them.
What you get
- Filing with the state
- The first year as your registered agent
Pros
- A year of registered agent service is in the price
- Registration line of $199, plus the state's fee
- Year-two agent amount: $99
Trade-offs
- Illinois only; your home state needs its own agent
- EIN application billed at $99
The 3 ratings summarized
| Line | Service | Rating | Service fee | Year two | Best for | Open |
|---|---|---|---|---|---|---|
| 1 | Illinois Registered Agent.co | 9.2 | $199 | $99/yr | The lowest agent renewal we rank here | Visit Illinois Registered Agent.coPartner link. We may earn money if you buy. |
| 2 | Mainstay Filing | 8.8 | $199 | $149/yr | Companies that register in several states | Visit Mainstay FilingPartner link. We may earn money if you buy. |
| 3 | IL Registered Agent.org | 8.5 | $199 | $99/yr | The lowest agent renewal we rank here | Visit IL Registered Agent.orgPartner link. We may earn money if you buy. |
Illinois foreign registration service amounts for 2026: year one, renewal and three-year sum
| Service | Year one | Year two | Year three | Three-year sum | Agent paid for year one |
|---|---|---|---|---|---|
| Illinois Registered Agent.co | $199 | $99 | $99 | $397 | Included |
| Mainstay Filing | $199 | $149 | $149 | $497 | Free |
| IL Registered Agent.org | $199 | $99 | $99 | $397 | Included |
Why the order looks like this
The rating method counts cost over years one to three and inclusions per price at 27% each and splits 46% among renewal price and terms, fit with state rules and price clarity. For Illinois, cost over years one to three was the deciding line.
Illinois Registered Agent.co sums to $397 across three years, $100 below Mainstay Filing. Both services include year one of agent service, so the renewal amount decided the order.
Each criterion and its weight is listed on How we rank.
Illinois foreign LLC registration: amount, form and office
A company from another state registers by lodging the Application for Admission to Transact Business (Form LLC-45.5) with the Illinois Secretary of State, Department of Business Services, Limited Liability Division; the state amount is $150. Illinois also needs certificate of Good Standing or Existence, issued inside 60 days of the filing.
Registration adds one recurring line: the annual report ($75), due within the 60 days before your anniversary month.
Have these ready
- Certificate of Good Standing or Existence, issued within 60 days before the filing.
- Home-state legal name, spelled exactly, and the formation date.
- An in-state registered agent; every service rated here can fill the role.
- $150 to the state, paid with the filing.
- The date of the annual report and its $75 fee on your calendar.
What skipping Illinois registration costs
An unregistered outside LLC may not sue in Illinois courts until it registers (805 ILCS 180/45-45(a)). Contracts it signs remain valid (805 ILCS 180/45-45(b)). Fees for the unregistered years are also owed.
Illinois foreign registration service: your questions
Is registration compulsory for an outside LLC doing business in Illinois?
Yes, once it does business there. An unregistered company cannot bring suit in the state's courts.
What are the costs of foreign registration in Illinois?
$150 to the state plus $199 to the service.
What form does Illinois use to register a foreign LLC?
the Illinois Secretary of State, Department of Business Services, Limited Liability Division handles it; the form's exact title is on the facts line above.
Must the filing include a home-state certificate for Illinois?
Yes: certificate of Good Standing or Existence, with an issue date within 60 days.
Must a registered agent stay on file after registering?
Yes. A registered agent with a street address in the state stays on record.
Which foreign registration service holds the top rating in Illinois?
Illinois Registered Agent.co, as $199 plus the state fee, year-one registered agent service included, then $99 a year for the agent.
Source lines
- Illinois Secretary of State, Department of Business Services, Limited Liability Division (ledger date August 2026)
- Illinois Secretary of State, Department of Business Services, Limited Liability Division (ledger date August 2026)
- 805 ILCS 180/5-5 (ledger date August 2026)
- Illinois formation fee: Filing fee, official source (ledger date October 2026)
- Illinois formation fee: Filing fee, official source (ledger date October 2026)
- Illinois registered agent statute (ledger date October 2026)
- Form LLC-45.5, Application for Admission (ledger date October 2026)
- Form LLC-45.40, Application for Withdrawal (ledger date October 2026)
- 805 ILCS 180/45-45, consequences of transacting business without admission (ledger date October 2026)
- 805 ILCS 180/45-47, activities that are not transacting business (ledger date October 2026)
- 805 ILCS 180/45-45 (ledger date November 2026)
- Illinois Registered Agent.co, pricing and service pages: amounts read November 12, 2026
- Mainstay Filing, Illinois service page: amounts read November 12, 2026
- IL Registered Agent.org, pricing and service pages: amounts read November 12, 2026