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Biz Formation Academy

A plain textbook on LLC paperwork, one state per chapter.

Textbook chapter 3 · Illinois

Foreign LLC Registration Chapter, Illinois (2026): 5 Sections and the 3 Best Services

In 2026 the services this chapter recommends for registering an LLC formed elsewhere in Illinois are Mainstay Filing ($199), Illinois Registered Agent.co ($199) and IL Registered Agent.org ($199), best first. 5 sections explain the filing, the $150 fee and the duties that follow.
Written by the Biz Formation Academy editorial board

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Registration fee $150 ilsos.gov, as published October 2026
Proof of good standing 60 days Must be issued within
Maintenance filing $75 Annual report
State cost, years 1 to 3 $300 Registration, reports and any minimum tax
Chapter sections 5 First to last

After this chapter you will understand

  • When an LLC from elsewhere must register in Illinois
  • The official form and fee
  • Remaining in good standing
  • How the recommended services compare

If you want someone else to file

The editorial board's five criteria are explained on how we grade and determine the order.

1. Mainstay Filing: best for LLCs that keep expanding

Top recommendation
Service $199; renewal $149 a year

Mainstay Filing comes first. The first-year agent is included, so the Illinois registration costs $199 beyond the state fee.

Compared with Illinois Registered Agent.co, the reader pays $100 more across three years and keeps fewer filings to prepare.

Year two brings a charge for the agent, $149 a year, and it is the same in every state.

Price covers

  • Registration is filed for you
  • The registered agent carries no charge in year one
  • The same price in every state

Advantages

  • $199 over Illinois's fee
  • All fifty states covered
  • The agent is free for the first year

Limitations

  • A higher agent renewal ($149)
Visit Mainstay Filing Partner link. We may earn money if you buy.

2. Illinois Registered Agent.co: best for a low yearly agent fee

Single-state plan
Service $199; renewal $99 a year

Illinois Registered Agent.co takes second position; registering with Illinois through this service costs $199 and includes a year of agent service; renewal is $99.

Price covers

  • The Illinois registration, prepared and submitted
  • A year of agent service is built into the price

Advantages

  • Then $99 per year
  • $199 to register
  • A year of agent service is included

Limitations

  • Nothing offered outside the state
Visit Illinois Registered Agent.co Partner link. We may earn money if you buy.

3. IL Registered Agent.org: best for another Illinois choice

Single-state plan
Service $199; renewal $99 a year

IL Registered Agent.org takes third position; registering with Illinois through this service costs $199 and includes a year of agent service; renewal is $99.

It publishes the same prices as Illinois Registered Agent.co.

Price covers

  • The Illinois registration, prepared and submitted
  • A year of agent service is built into the price

Advantages

  • A year of agent service is included
  • Then $99 per year
  • $199 to register

Limitations

  • Nothing offered outside the state
Visit IL Registered Agent.org Partner link. We may earn money if you buy.

Rankings and prices together

#ServiceFirst yearFrom year twoThree-year total
1 Mainstay Filing $199$149/yr$497 Visit Mainstay Filing Partner link. We may earn money if you buy.
2 Illinois Registered Agent.co $199$99/yr$397 Visit Illinois Registered Agent.co Partner link. We may earn money if you buy.
3 IL Registered Agent.org $199$99/yr$397 Visit IL Registered Agent.org Partner link. We may earn money if you buy.

Prices come from each company's own site, consulted November 13, 2026. Every row also owes the $150 state fee.

Registering with Illinois, section by section

  1. Section 1

    Decide if the LLC must register

    Foreign registration is the filing by which an LLC formed outside Illinois is authorized to do business in Illinois. The consequences of failing to register include: until registered, the LLC cannot bring suit before Illinois's courts (805 ILCS 180/45-45(a)) agreements already made are not voided (805 ILCS 180/45-45(b)) fees owed for the time before registration

    Reference: ilga.gov, as published October 2026

  2. Section 2

    Request the home-state certificate

    The application must include certificate of Good Standing or Existence, no older than 60 days.

    A recent certificate is safest, so order it late.

  3. Section 3

    Appoint a registered agent for Illinois

    Every LLC must name a registered agent with an in-state street address. The address has to be a registered office in Illinois that matches the agent's business office. A P.O. box alone is not accepted.

    Every recommended service provides the registered agent.

    Reference: ilga.gov, as published October 2026

  4. Section 4

    Section four is the Application for Admission to Transact Business

    the Illinois Secretary of State, Department of Business Services, Limited Liability Division is the office that receives the filing and $150.

    Reference: ilsos.gov, as published October 2026

  5. Section 5

    Remain registered

    What follows registration is the annual report, priced at $75, with timing of within the 60 days before your anniversary month.

Costs section by section

ItemWho is paidPrice
Registering the LLC State agency$150
Annual report State agency$75
Filing service (optional) Your chosen service$199 in year one
State fees for the first three years State agency$300

State fees come from the official pages in the bibliography. Over three years they consist of the filing, two reports and, in a few states, a minimum tax.

How the ranking came out

On chapters the price completes (30% of the ranking) came first, with next.

The LLC is active in two states, and reach settled the order.

Common questions

How much must an LLC formed elsewhere pay to register with Illinois?

$150 in state fees. A service adds $199.

Which form do I file to register?

Look for the Application for Admission to Transact Business (Form LLC-45.5); it is sent to 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, issued within 60 days of filing.

What if the LLC does business there without registering?

until registered, the LLC cannot bring suit before Illinois's courts (805 ILCS 180/45-45(a)) agreements already made are not voided (805 ILCS 180/45-45(b)) fees owed for the time before registration

What is due after registering?

Plan for the annual report, which costs $75.

Which service should handle the registration?

The ranking is Mainstay Filing, Illinois Registered Agent.co and IL Registered Agent.org, and Mainstay Filing is first since the service fee is $199 plus the state's own fee, the registered agent is free for year one, and the later price is $149 a year.

Further reading

Bibliography and primary texts

  1. Primary text behind Illinois Secretary of State, Department of Business Services: ilsos.gov, accessed August 2026.
  2. Primary text behind Illinois Secretary of State, Department of Business Services: ilsos.gov, accessed August 2026.
  3. Primary text behind 805 ILCS 180/5-5: ilga.gov, accessed August 2026.
  4. Primary text behind Illinois formation fee: Filing fee, official source: ilga.gov, accessed October 2026.
  5. Primary text behind Illinois formation fee: Filing fee, official source: ilsos.gov, accessed October 2026.
  6. Primary text behind Illinois registered agent statute: ilga.gov, accessed October 2026.
  7. Primary text behind Form LLC-45.5, Application for Admission: ilsos.gov, accessed October 2026.
  8. Primary text behind Form LLC-45.40, Application for Withdrawal: ilsos.gov, accessed October 2026.
  9. Primary text behind 805 ILCS 180/45-45, consequences of transacting business without: ilga.gov, accessed October 2026.
  10. Primary text behind 805 ILCS 180/45-47, activities that are not transacting: ilga.gov, accessed October 2026.
  11. Primary text behind 805 ILCS 180/45-45: ilga.gov, accessed November 2026.
  12. Prices quoted from the Illinois service page at Mainstay Filing on November 13, 2026
  13. Prices quoted from the pricing page at Illinois Registered Agent.co on November 13, 2026
  14. Prices quoted from the pricing page at IL Registered Agent.org on November 13, 2026