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Biz Formation Academy

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

Chapter 1 · Illinois

Illinois LLC Formation Chapter (2026): 7 Sections and the 3 Best LLC Services

The recommended reading for forming an LLC in Illinois in 2026 is Illinois Registered Agent.co ($199), IL Registered Agent.org ($199) and Mainstay Filing ($199), in that order. The chapter has 7 sections. Illinois charges $150 to file, and the Limited Liability Company Annual Report follows every year.
Written by the Biz Formation Academy editorial board

Key facts for this chapter

Fee to form $150 See ilsos.gov; page last consulted October 2026
Limited Liability Company Annual Report $75 a year Stated timing: before the first day of the entity's anniversary month
What the state collects over three years $300 Service fees excluded
Chapter sections 7 Outlined below

Chapter objectives

  • What Illinois charges to form an LLC and where the filing goes
  • The registered agent requirement
  • What is filed every year afterward
  • How the recommended services compare

Who we recommend in Illinois

Ranked by the grading page: three-year cost (34%), paperwork completed (30%), second-year price, fit with Illinois rules and clarity of the price list.

1. Illinois Registered Agent.co: best for a basic formation

Highest ranked
$199 in year one, $99 afterward

In Illinois, Illinois Registered Agent.co heads the list: forming a Illinois LLC costs $199 and the agent for year one is part of that price; the agent renews at $99.

On three-year cost it undercuts Mainstay Filing, and cost is a large part of the ranking.

The price stops short of the Limited Liability Company Annual Report.

Price covers

  • The filing is made for you
  • One year of agent service is built into the price

Advantages

  • $99 a year after that
  • $199 plus the state fee
  • Year-one agent service at no added cost

Limitations

  • The Limited Liability Company Annual Report is left for the owner to file
  • The EIN application costs $99 extra
Visit Illinois Registered Agent.co Partner link. We may earn money if you buy.

2. IL Registered Agent.org: best for a small agent renewal

Single-state plan
$199 in year one, $99 afterward

IL Registered Agent.org takes second position; forming a Illinois LLC costs $199 and the agent for year one is part of that price; the agent renews at $99.

The price stops short of the Limited Liability Company Annual Report.

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

Price covers

  • The filing is made for you
  • One year of agent service is built into the price

Advantages

  • $199 plus the state fee
  • Year-one agent service at no added cost
  • $99 a year after that

Limitations

  • The Limited Liability Company Annual Report is left for the owner to file
  • The EIN application costs $99 extra
Visit IL Registered Agent.org Partner link. We may earn money if you buy.

3. Mainstay Filing: best for a first year with little paperwork

Serves all states
$199 annually and the $150 state fee

Mainstay Filing takes third position; $199 per year takes care of three chapters at once: formation, registered agent and the annual report.

Across three years it trails Illinois Registered Agent.co by $200.

Included: the Limited Liability Company Annual Report; the state's $75 is charged exactly as Illinois sets it.

Price covers

  • Formation paperwork completed
  • Registered agent for the full year
  • Annual report prepared and filed
  • The EIN application is part of the price
  • State fee billed at cost

Advantages

  • Renews at $199
  • The EIN application is filed for you
  • A single yearly fee of $199, with the annual report included

Limitations

  • After year one it costs $100 more annually
Visit Mainstay Filing Partner link. We may earn money if you buy.

The services compared

#ServiceFirst yearFrom year twoThree-year total
1 Illinois Registered Agent.co $199$99/yr$397 Visit Illinois Registered Agent.co Partner link. We may earn money if you buy.
2 IL Registered Agent.org $199$99/yr$397 Visit IL Registered Agent.org Partner link. We may earn money if you buy.
3 Mainstay Filing $199$199/yr$597 Visit Mainstay Filing Partner link. We may earn money if you buy.

Taken from each company's price page on November 13, 2026. Each row still owes Illinois's $150 fee.

The sections

  1. Section 1

    Confirm the name is not taken

    Check the name against the Illinois register kept by the Illinois Secretary of State; this avoids a rejected filing.

    Consider whether a matching web address is available too.

  2. Section 2

    Select a registered agent for the LLC

    Every LLC must name a registered agent with an in-state street address. An Illinois resident, or a business authorized to do business in Illinois. The LLC cannot act as its own agent.

    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.

    Providing the registered agent is part of what each recommended service sells.

    Reference: See ilga.gov; page last consulted October 2026

  3. Section 3

    Decide between self-filing and a service

    Without a service the charge is the state's $150. With a recommended service it grows by $199.

  4. Section 4

    Next comes the Articles of Organization

    Formation takes effect when the Illinois Secretary of State accepts the Articles of Organization (Form LLC-5.5) and $150 under 805 ILCS 180/5-5.

    Reference: See ilsos.gov; page last consulted October 2026

  5. Section 5

    Request an Employer Identification Number from the IRS

    After formation, an EIN identifies the LLC to the IRS and lets it open accounts in its own name. The Mainstay Filing annual price already includes this section.

  6. Section 6

    Record how the company will be run

    Think of the operating agreement as the owners' written rules. The company keeps it; the state does not ask for a copy.

  7. Section 7

    Maintain good standing in Illinois

    Calendar entry for the owner: the Limited Liability Company Annual Report, at $75, every year, due before the first day of the entity's anniversary month. Lateness is penalized at $100.

    Reference: See ilsos.gov; page last consulted October 2026

Illinois costs by section

Line itemRecipientTotal
Section on formation State agency$150
Limited Liability Company Annual Report State agency$75 every year
Late charge State agency$100
Paid assistance The service$199 initially
Three-year state total State agency$300

The three-year state row is computed as the filing fee, plus the report in each of years two and three, plus any yearly minimum tax. Service fees have their own rows.

How the Illinois recommendations were ranked

Tuition over three years decided first place in Illinois. It is 34% of the ranking, and the rest comes from chapters the price completes, second-year bill, fit for the state syllabus and clarity of the price list.

Illinois Registered Agent.co leads the cost criterion at $397 across three years, with Mainstay Filing $200 behind.

Common questions

What does Illinois charge to form an LLC?

$150, paid to the state. $199 more buys someone who prepares the filing.

Which form creates the LLC?

Deliver the Articles of Organization (Form LLC-5.5) to the Illinois Secretary of State.

Is a registered agent required?

Every LLC must name a registered agent with an in-state street address.

What does Illinois require each year?

Submit the Limited Liability Company Annual Report every year; cost $75, deadline before the first day of the entity's anniversary month.

Can I form the LLC without a service?

Nothing prevents it. Illinois asks $150, and the LLC must name a registered agent, which the owner can be or can hire out.

Which LLC service should a first-time founder use?

Illinois Registered Agent.co, because the filing price is $199, and later years of agent service are $99 each. After it come IL Registered Agent.org and Mainstay Filing.

Next chapter

Bibliography and primary texts

  1. Footnote for Illinois Secretary of State, Department of Business Services: see ilsos.gov (August 2026).
  2. Footnote for Illinois Secretary of State, Department of Business Services: see ilsos.gov (August 2026).
  3. Footnote for 805 ILCS 180/5-5: see ilga.gov (August 2026).
  4. Footnote for Illinois formation fee: Filing fee, official source: see ilga.gov (October 2026).
  5. Footnote for Illinois formation fee: Filing fee, official source: see ilsos.gov (October 2026).
  6. Footnote for Illinois registered agent statute: see ilga.gov (October 2026).
  7. Price reference: Illinois Registered Agent.co, pricing page, November 13, 2026
  8. Price reference: IL Registered Agent.org, pricing page, November 13, 2026
  9. Price reference: Mainstay Filing, Illinois service page, November 13, 2026