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Business Basics LabLLC paperwork, measured state by state.

Lab sheet 2 · Illinois

The Illinois Registered Agent (2026): 6 Procedures and the 3 Best Agents

For appointing a registered agent in Illinois in 2026, the lab recommends Mainstay Filing ($149 a year), IL Registered Agent.org ($99 a year) and Illinois Registered Agent.co ($99 a year), highest reading first. The sheet runs 6 procedures: the legal rule, eligibility, the address test and the filing.

Recorded by the Business Basics Lab staff ·

Sheet summary

Required by law
YesReference ilga.gov, October 2026
Yearly cost of the ranked services
$99 to $149 a yearPublished prices
Limited Liability Company Annual Report
$75 a yearReference ilsos.gov, October 2026
Procedures
6From first to last

On this sheet

  • Why Illinois requires an agent on file
  • The eligibility and address rules
  • How to name or change the agent
  • The ranked agents

Best reading

The Illinois results

Three-year cost and the number of procedures a price performs weigh the most; how we measure lists all five criteria.
Strongest result

1. Mainstay Filing: best for LLCs that may enter other states

$149 yearly, identical at renewal

Top of the Illinois readings is Mainstay Filing: a constant $149 a year regardless of the state of formation.

Three years run $150 higher than at IL Registered Agent.org, in exchange for more of the work being done.

What the price performs

  • An office address inside the state
  • Papers served on the company are scanned free on the same business day
  • Three government letters a year are scanned at no charge
  • Also serves nonprofits, corporations, LPs and LLPs

Measured strengths

  • $149 yearly with no increase
  • The same price in all fifty states

Measured limits

  • Costs $50 more every year
  • The owner still files the reports
Visit Mainstay FilingPartner link. We may earn money if you buy.
In-state service

2. IL Registered Agent.org: best for cost-conscious owners

$99 yearly, identical at renewal

IL Registered Agent.org is an acceptable second choice: a one-state plan reading $99 a year and $99 at renewal.

What the price performs

  • A physical Illinois address
  • Served documents made available online

Measured strengths

  • $99 a year with no increase
  • Costs less per year than Mainstay Filing

Measured limits

  • Illinois only; every other state needs its own agent
  • Filing the Limited Liability Company Annual Report is outside its service
Visit IL Registered Agent.orgPartner link. We may earn money if you buy.
In-state service

3. Illinois Registered Agent.co: best for a street address inside the state

$99 yearly, identical at renewal

Illinois Registered Agent.co is an acceptable third choice: a one-state plan reading $99 a year and $99 at renewal.

It costs exactly what IL Registered Agent.org costs.

What the price performs

  • A physical Illinois address
  • Served documents made available online

Measured strengths

  • Costs less per year than Mainstay Filing
  • $99 a year with no increase

Measured limits

  • Illinois only; every other state needs its own agent
  • Filing the Limited Liability Company Annual Report is outside its service
Visit Illinois Registered Agent.coPartner link. We may earn money if you buy.

The 3 ranked services side by side

#ServiceAnnual priceRenewal priceThree-year total
1Mainstay Filing$149$149/yr$447Visit Mainstay FilingPartner link. We may earn money if you buy.
2IL Registered Agent.org$99$99/yr$297Visit IL Registered Agent.orgPartner link. We may earn money if you buy.
3Illinois Registered Agent.co$99$99/yr$297Visit Illinois Registered Agent.coPartner link. We may earn money if you buy.
Each company's listed price on November 13, 2026. Changing agent leaves state fees unchanged.

Appointing an Illinois registered agent, procedure by procedure

  1. Procedure 1: What Illinois requires of an agent

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

    Specimen: Reference ilga.gov, October 2026

  2. Procedure 2: Who can take the role

    An Illinois resident, or a business authorized to do business in Illinois. The LLC cannot act as its own agent. Statutory basis: 805 ILCS 180/1-35.

  3. Procedure 3: The address requirement

    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.

    TipWith a service, the record shows its address instead of the owner's.

  4. Procedure 4: Self-service or a professional agent

    The ranked agents cost $99 to $149 a year; personal service is the alternative for those who qualify.

  5. Procedure 5: Record the agent with the state

    The agent is identified in the filing made with the Illinois Secretary of State, and any change is a distinct filing there.

    Specimen: Reference ilsos.gov, October 2026

  6. Procedure 6: Maintain accurate details

    State correspondence about the Limited Liability Company Annual Report arrives with the registered agent. Its price is $75 every year, with the due date given as before the first day of the entity's anniversary month.

    Specimen: Reference ilsos.gov, October 2026

The cost of this sheet

Cost itemRecipientPrice
Engaging an agentThe engaged service$99 to $149 a year
From year twoThe engaged service$99 to $149 a year
Limited Liability Company Annual ReportTo the state$75 every year
Every state amount here can be verified against the specimens below. The three-year row combines formation, two later reports and a minimum tax where one exists, and it never includes service prices.

Why this order

prevailed on procedures the price performs (28% of the reading), with close behind.

One agent for any state defeated the one-state option.

Common questions

Does Illinois law require a registered agent for an LLC?

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

Can I be my own registered agent?

Owners may serve when qualified; procedures 2 and 3 give the tests.

Can I change my registered agent later?

Yes, at any time. Procedure 5 explains how to file the change with the Illinois Secretary of State.

What does a registered agent cost in Illinois?

From $99 to $149 a year on this sheet.

What does the LLC pay the state each year?

Chiefly the Limited Liability Company Annual Report, $75 every year.

Which registered agent would you choose?

The order of the readings is Mainstay Filing, IL Registered Agent.org and Illinois Registered Agent.co. Mainstay Filing is first because $149 a year, and the reading is unchanged for states added later.

Next sheet

Specimens and records

  1. Notebook entry for Illinois Secretary of State, Department of Business Services: the observations rest on ilsos.gov, revisited in August 2026. Replicate the check by opening that page.
  2. Notebook entry for Illinois Secretary of State, Department of Business Services: the observations rest on ilsos.gov, revisited in August 2026. Replicate the check by opening that page.
  3. Notebook entry for 805 ILCS 180/5-5: the observations rest on ilga.gov, revisited in August 2026. Replicate the check by opening that page.
  4. Notebook entry for Illinois formation fee: Filing fee, official source: the observations rest on ilga.gov, revisited in October 2026. Replicate the check by opening that page.
  5. Notebook entry for Illinois formation fee: Filing fee, official source: the observations rest on ilsos.gov, revisited in October 2026. Replicate the check by opening that page.
  6. Notebook entry for Illinois registered agent statute: the observations rest on ilga.gov, revisited in October 2026. Replicate the check by opening that page.
  7. Observation of Mainstay Filing's Illinois service page, November 13, 2026
  8. Observation of IL Registered Agent.org's pricing page, November 13, 2026
  9. Observation of Illinois Registered Agent.co's pricing page, November 13, 2026