Skip to content
Plain CharterLLC questions, short answers.

Plain answers · Illinois

3 Best Foreign Registration Services in Illinois (2026), Plainly Answered

We'd pick Mainstay Filing ($199), Illinois Registered Agent.co ($199) and IL Registered Agent.org ($199) in Illinois for 2026, in that order. Every option pays Illinois's $150; three years of service run $397 to $497.

By the Plain Charter editorial team ·

Quick answer

Registration fee
$150
Home-state certificate?
Needed (60 days old at most)
Each year after
$75, annual report
Our order
Mainstay Filing, Illinois Registered Agent.co then IL Registered Agent.org

The Illinois picks

Ranked by how we choose: three-year cost first, then what the price covers.
1First choice

1. Mainstay Filing: best for a second state and a third

First year $199, then $149 a year

Mainstay Filing is the one we'd hire first in Illinois, because it charges $199 on top of the state fee and includes the registered agent free for the first year, then $149 a year.

The extra $100 over three years, compared with Illinois Registered Agent.co, pays for coverage beyond Illinois.

After the free year, the registered agent renews at $149 a year.

The price covers

  • State registration
  • Registered agent, first year free
  • Available in all fifty states

Upsides

  • Service fee $199
  • Ready for the next state
  • Agent included for year one

What to weigh

  • Agent renews at $149, $50 over Illinois Registered Agent.co
Visit Mainstay FilingPartner link. We may earn money if you buy.
2One-state plan

2. Illinois Registered Agent.co: best for adding just this state

First year $199, then $99 a year

Illinois Registered Agent.co is next: three years of service fees come to $397.

The price covers

  • Your foreign filing
  • A year of agent service

Upsides

  • First agent year in the price
  • $199 to register
  • $99 a year from year two

What to weigh

  • Illinois only; the home state needs its own agent
Visit Illinois Registered Agent.coPartner link. We may earn money if you buy.
3One-state plan

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

First year $199, then $99 a year

IL Registered Agent.org is next: three years of service fees come to $397.

Price for price it ties Illinois Registered Agent.co.

The price covers

  • Your foreign filing
  • A year of agent service

Upsides

  • First agent year in the price
  • $99 a year from year two
  • $199 to register

What to weigh

  • Illinois only; the home state needs its own agent
Visit IL Registered Agent.orgPartner link. We may earn money if you buy.

Prices together

#PickYear 1RenewalThree yearsYou get
1Mainstay Filing$199$149/yr$497state registration; registered agent, first year free; available in all fifty statesVisit Mainstay FilingPartner link. We may earn money if you buy.
2Illinois Registered Agent.co$199$99/yr$397your foreign filing; A year of agent serviceVisit Illinois Registered Agent.coPartner link. We may earn money if you buy.
3IL Registered Agent.org$199$99/yr$397your foreign filing; A year of agent serviceVisit IL Registered Agent.orgPartner link. We may earn money if you buy.
Each company's published prices, November 12, 2026. State fees come on top and do not change by pick.

Your questions

When does an out-of-state LLC have to register here?

An LLC from another state registers before it transacts business in Illinois.

Without it: the courts stay closed to its claims (805 ILCS 180/45-45(a)); back fees.

October 2026 · ilga.gov

How much is foreign registration?

$150 in state fees and $199 for a service.

The three-year state total is $300. October 2026 · ilsos.gov

What gets filed?

It takes one filing, the Application for Admission to Transact Business (Form LLC-45.5), which goes to the Illinois Secretary of State, Department of Business Services, Limited Liability Division.

It needs certificate of Good Standing or Existence dated within 60 days.

What comes due after registering?

Annual report: $75.

Due: Within the 60 days before your anniversary month.

Why this order?

Because of what the price takes off your plate: Mainstay Filing does best there, and it counts for 30%.

Most of our weighting sits on three-year cost and what the price takes off your plate.

Illinois Registered Agent.co serves Illinois only, so your home state would need someone else.

See how we rank

What Illinois requires

RequirementAnswerOfficial source
Registration filing$150October 2026 · ilsos.gov
Good standing proofNeeded, 60 daysOctober 2026 · ilga.gov
Annual report$75October 2026 · ilga.gov
Paid to the state by year 3$300Computed from the rows
Three-year state total = filing + reports in years 2 and 3 + any minimum tax; variable costs are not added.

Other quick questions

Do both states need an agent?

Usually, yes. One national provider can serve both; a local one cannot.

How do the three-year costs compare?

Mainstay Filing $497, Illinois Registered Agent.co $397 and IL Registered Agent.org $397, before state fees.

What are the numbers based on?

Illinois's own publications for the state side, published company prices for the rest.

Do I have to use a service?

No law requires one. A service is a convenience.

Can a service file the registration for me?

Yes. Each pick here files it for you; the state fee is the same either way.

Which foreign registration service would you pick in Illinois?

Mainstay Filing, because its $199 fee is the same in any state, with year one of registered agent service included. Then Illinois Registered Agent.co and IL Registered Agent.org.

Cited sources

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