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Filing Verdict

Rankings of registered agents, LLC formation and foreign registration services in all 50 states.

Foreign registration verdict · Illinois

3 Best Foreign Registration Services in Illinois (2026)

Filing Verdict's 2026 verdict on foreign registration services in Illinois: Mainstay Filing ($199), Illinois Registered Agent.co ($199) and IL Registered Agent.org ($199), in that order. Mainstay Filing takes first place: $199 on top of the state fee, the same in any state, with the first year of registered agent service included.
The Filing Verdict editorial team
Our top pick
Spot 1

1. Mainstay Filing: best for companies working in several states

Service fee $199, $349 due at checkout with the state fee; agent $149 yearly after year one

9.6Editorial score
out of 10

Mainstay Filing wins here: $199 plus the state's own fee, with the registered agent free for the first year and one price in every state.

After the free first year the agent is $149 a year, whichever state you register in.

The three-year bill is $100 higher than Illinois Registered Agent.co's, and the wider coverage is worth that to us.

What you get

  • The registration, prepared and submitted for you
  • Free registered agent service for the first year
  • Any legal papers served on the company are scanned the same business day for free

What we like

  • Same-business-day scans of served papers, free
  • One price in all fifty states
  • Service fee of $199, plus the state's fee
  • Registered agent service free in year one

Cons

  • After year one its agent runs $149 a year, $50 above Illinois Registered Agent.co
Visit Mainstay FilingPartner link. We may earn money if you buy. Our full Mainstay Filing verdict
Best for an Illinois-only company
Spot 2

2. Illinois Registered Agent.co: best for companies adding only Illinois

$199 service fee, state fee added; $99 a year from year two

9.2Editorial score
out of 10

Second place goes to Illinois Registered Agent.co: the Illinois registration for $199 with the first agent year included, then $99 a year.

The plan gives the company an in-state street address as its registered office, and papers served on the company are scanned to your online account.

What you get

  • Registration prepared and filed
  • Year-one registered agent service

What we like

  • Files the registration for $199 plus fees
  • $99 per year keeps the agent from year two
  • Includes the first year as your registered agent

Cons

  • Covers Illinois only; your home state needs its own agent
  • The EIN application is billed separately ($99)
Visit Illinois Registered Agent.coPartner link. We may earn money if you buy. Our full Illinois Registered Agent.co verdict
Best for an Illinois-only company
Spot 3

3. IL Registered Agent.org: best for Illinois registrations only

$199 service fee, state fee added; $99 a year from year two

9.0Editorial score
out of 10

Third place goes to IL Registered Agent.org: the Illinois registration for $199 with the first agent year included, then $99 a year.

The plan gives the company an in-state street address as its registered office, and papers served on the company are scanned to your online account.

IL Registered Agent.org copies Illinois Registered Agent.co on price and plan features, so the order between them is a close call.

What you get

  • Registration prepared and filed
  • One year of registered agent service

What we like

  • $199 to register, plus the state's fee
  • Then $99 a year for agent service
  • A year of registered agent service is part of the price

Cons

  • Covers Illinois only; your home state needs its own agent
  • The EIN application is billed separately ($99)
Visit IL Registered Agent.orgPartner link. We may earn money if you buy. Our full IL Registered Agent.org verdict

The 3 verdicts at a glance

No.ServiceVerdict scoreService feeYear twoBest forVisit
1Mainstay Filing9.6$199$149/yrCompanies registered in several states Visit Mainstay FilingPartner link. We may earn money if you buy.
2Illinois Registered Agent.co9.2$199$99/yrThe lowest agent renewal here Visit Illinois Registered Agent.coPartner link. We may earn money if you buy.
3IL Registered Agent.org9.0$199$99/yrThe lowest agent renewal here Visit IL Registered Agent.orgPartner link. We may earn money if you buy.
Each mark out of 10 is our own judgment from the weighted criteria on How we rank. None of it comes from customer ratings.

Illinois foreign registration service prices for 2026: year one, renewals and three years

ServiceYear 1Year 2Year 3Total, 3 yearsAgent covered in year one
Mainstay Filing$199$149$149$497Free
Illinois Registered Agent.co$199$99$99$397Included
IL Registered Agent.org$199$99$99$397Included
Prices were read from each company's own pages on November 12, 2026. Illinois's $150 registration fee goes on top of every row and is not counted in these totals.

Why this order

What settled Illinois: paperwork the price handles. The method puts 35% on total over three years, 35% on paperwork the price handles and spreads 30% across renewal behavior, match to the state and up-front pricing.

Registering in a second state involves two states, so one provider with one price in both scored best on coverage, ahead of Illinois Registered Agent.co.

The full list of criteria and weights is on How we rank.

Illinois foreign LLC registration: the fee, the form and the filing office

The company 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 asks for certificate of Good Standing or Existence, issued within 60 days of filing.

Afterwards the company files the annual report ($75), due within the 60 days before your anniversary month.

Before you file: a checklist

  • Certificate of Good Standing or Existence, issued within 60 days before you file.
  • The exact legal name from the home state, and the date the company was formed there.
  • A registered agent with a street address in the state; each service on this page can act in that role.
  • The $150 state fee, paid with the filing.
  • A calendar entry for the annual report and its $75 fee.

What skipping Illinois registration can cost

Until it registers, an out-of-state LLC cannot bring suit in Illinois courts (805 ILCS 180/45-45(a)). Contracts it signs stay valid (805 ILCS 180/45-45(b)). Back fees for the period it operated unregistered are also due.

Illinois foreign registration service: questions answered

Does Illinois require an out-of-state LLC to register?

Yes, once it transacts business there. Until it registers, it cannot bring suit in the state's courts.

What does foreign registration cost in Illinois?

The state fee is $150, and the service fee is $199.

Which form does Illinois use for foreign registration?

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.

Does Illinois want a certificate from my home state?

Yes. It asks for certificate of Good Standing or Existence, issued within 60 days of filing.

Is a registered agent required once I have registered?

Yes. The company still needs a registered agent here, with a street address in the state.

Which foreign registration service is the best pick in Illinois?

Mainstay Filing, because it prepares the Illinois registration for $199 and serves as your registered agent, free in year one, then $149 a year.

Read next

Sources and dates

  1. Illinois Secretary of State, Department of Business Services, Limited Liability Division, confirmed August 2026
  2. Illinois Secretary of State, Department of Business Services, Limited Liability Division, confirmed August 2026
  3. 805 ILCS 180/5-5, confirmed August 2026
  4. Illinois formation fee: Filing fee, official source, confirmed October 2026
  5. Illinois formation fee: Filing fee, official source, confirmed October 2026
  6. Illinois registered agent statute, confirmed October 2026
  7. Form LLC-45.5, Application for Admission, confirmed October 2026
  8. Form LLC-45.40, Application for Withdrawal, confirmed October 2026
  9. 805 ILCS 180/45-45, consequences of transacting business without admission, confirmed October 2026
  10. 805 ILCS 180/45-47, activities that are not transacting business, confirmed October 2026
  11. 805 ILCS 180/45-45, confirmed November 2026
  12. Checked November 12, 2026: Mainstay Filing, Illinois service page
  13. Checked November 12, 2026: Illinois Registered Agent.co, pricing and service pages
  14. Checked November 12, 2026: IL Registered Agent.org, pricing and service pages