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Plain talk · Illinois

3 Best Foreign Registration Services in Illinois (2026), Simply Ranked

For foreign registration services in Illinois, here is our 2026 ranking: Mainstay Filing ($199), Illinois Registered Agent.co ($199) and IL Registered Agent.org ($199). You'll pay the state $150 to register whoever files, plus $397 to $497 in service fees across three years.
From the LLC Plainly editorial team

Quick take

State registration fee
$150
Attach a certificate?
Required (60 days or newer)
What comes next
$75, annual report
Who to use
Mainstay Filing, Illinois Registered Agent.co then IL Registered Agent.org

Who we like in Illinois

The order comes from our five checks: three-year cost first, then how much the price covers.
Best overall

1. Mainstay Filing: best for the same fee anywhere

$199 up front, then $149 a year

Number one is Mainstay Filing, since registration is $199, and the registered agent costs nothing until year two.

Going with Illinois Registered Agent.co saves $100 over three years, but only a Illinois company can use it.

The registered agent costs nothing the first year. After that it's $149 a year, in any state.

Your money buys

  • Registration paperwork done
  • Registered agent, free in year one
  • One service fee in all fifty states

The good

  • Fifty states covered
  • $199 on top of Illinois's fee
  • Agent covered for year one

Trade-offs

  • A pricier agent renewal at $149
A Illinois favorite

2. Illinois Registered Agent.co: best for a lean registration

$199 up front, then $99 a year

Illinois Registered Agent.co takes second, because $199 files the registration, and the agent costs $99 each year after.

Your money buys

  • State registration done
  • First-year agent comes with it

The good

  • You don't pay for an agent in year one
  • A service fee of $199
  • Then $99 a year for the agent

Trade-offs

  • You'll need another company for your home state
A Illinois favorite

3. IL Registered Agent.org: best for a second in-state option

$199 up front, then $99 a year

IL Registered Agent.org takes third, because $199 files the registration, and the agent costs $99 each year after.

Its prices match Illinois Registered Agent.co exactly, so either one works.

Your money buys

  • State registration done
  • First-year agent comes with it

The good

  • You don't pay for an agent in year one
  • Then $99 a year for the agent
  • A service fee of $199

Trade-offs

  • You'll need another company for your home state

Price check

#CompanyStart priceRenews atThree-year totalIn the price
1Mainstay Filing$199$149/yr$497registration paperwork done; registered agent, free in year one; one service fee in all fifty statesHead to Mainstay FilingPartner link. We may earn money if you buy.
2Illinois Registered Agent.co$199$99/yr$397state registration done; First-year agent comes with itHead to Illinois Registered Agent.coPartner link. We may earn money if you buy.
3IL Registered Agent.org$199$99/yr$397state registration done; First-year agent comes with itHead to IL Registered Agent.orgPartner link. We may earn money if you buy.
We read these prices on November 13, 2026. Three years means year one plus two renewals.

What you probably want to know

Who has to register in this state?

Doing business in Illinois with an LLC formed somewhere else means registering at the start.

If you skip registering, you could face its access to Illinois courts as a plaintiff is cut off (805 ILCS 180/45-45(a)); back fees owed for the gap before registering.

ilga.gov · October 2026 · checked

How much should I put aside to register?

State fee $150; service $199 extra.

Three years of state charges: $300. ilsos.gov · October 2026 · checked

What gets submitted?

The Illinois Secretary of State, Department of Business Services, Limited Liability Division handles the Application for Admission to Transact Business (Form LLC-45.5), and one filing does it.

The filing needs certificate of Good Standing or Existence newer than 60 days.

What does staying registered cost?

Next up is the annual report, at $75.

Filings come due Within the 60 days before your anniversary month.

Why is the list in this order?

It comes down to work taken off your hands, and Mainstay Filing is best at it.

Five checks set the order: cost across three years (33%), work taken off your hands (31%), prices stated clearly (14%), renewal price (12%) and where it works (10%).

Illinois Registered Agent.co only covers Illinois, so you'd need someone else at home.

See how we score

Illinois requirements, with sources

The ruleDetailsWhere we found it
State filing fee$150ilsos.gov · October 2026 · checked
Document from your home stateRequired, 60 daysilga.gov · October 2026 · checked
Annual report$75ilga.gov · October 2026 · checked
Three-year state total$300Our total of the lines above
How we get the bottom line: filing + report in year two + report in year three + any minimum tax. Open-ended costs are described in the text only.

More questions

Does my home state need an agent too?

Most likely yes. A national provider can look after the home state and this one together.

What's each pick's bill across three years?

Mainstay Filing: $497 / Illinois Registered Agent.co: $397 / IL Registered Agent.org: $397, not counting state fees.

Where did you get these numbers?

Illinois's fee schedules and forms for state costs; each company's price page for service costs.

Do I need to hire a service?

It's your call. You can file on your own if you meet the rules on this page.

Who actually submits the registration?

Yes. Every pick prepares and files it, and the state fee is the same no matter who you pick.

Who would you go with in Illinois?

Mainstay Filing wins on work taken off your hands, ahead of Illinois Registered Agent.co and IL Registered Agent.org.

Check our work

  1. ilsos.gov: the page for Illinois Secretary of State, Department, seen August 2026
  2. ilsos.gov: the page for Illinois Secretary of State, Department, seen August 2026
  3. ilga.gov: the page for 805 ILCS 180/5-5, seen August 2026
  4. ilga.gov: the page for Illinois formation fee: Filing fee, seen October 2026
  5. ilsos.gov: the page for Illinois formation fee: Filing fee, seen October 2026
  6. ilga.gov: the page for Illinois registered agent statute, seen October 2026
  7. ilsos.gov: the page for Form LLC-45.5, Application for Admission, seen October 2026
  8. ilsos.gov: the page for Form LLC-45.40, Application for Withdrawal, seen October 2026
  9. ilga.gov: the page for 805 ILCS 180/45-45, consequences of, seen October 2026
  10. ilga.gov: the page for 805 ILCS 180/45-47, activities that, seen October 2026
  11. ilga.gov: the page for 805 ILCS 180/45-45, seen November 2026
  12. We read the Mainstay Filing Illinois service page on November 13, 2026
  13. We read the Illinois Registered Agent.co pricing page on November 13, 2026
  14. We read the IL Registered Agent.org pricing page on November 13, 2026