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Biz Formation Report

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

Registered agents report · Illinois

3 Best Registered Agents in Illinois (2026)

By the Biz Formation Report editorial team

Biz Formation Report ranks registered agents in Illinois for 2026 as IL Registered Agent.org ($99 a year), Illinois Registered Agent.co ($99 a year) and Mainstay Filing ($149 a year), in that order. IL Registered Agent.org earns the top grade: $99 a year with no renewal increase, the lowest yearly price on this list.

No.1

Number one here

1. IL Registered Agent.org: best for the lowest annual price on this list

Score9.3out of 10
$99 a year, unchanged at renewal

Top grade, IL Registered Agent.org: an Illinois-focused agent at $99 a year, supplying an in-state street address for the registered office.

Served legal papers go to the in-state address IL Registered Agent.org provides, and you receive scans of them online.

Three years of service cost less here than with Mainstay Filing, and cost counts heavily in the grade.

What you get

  • A street address in the state, on the public record
  • Served legal documents are scanned and made available online

Good

  • Beats Mainstay Filing on yearly cost
  • LLC formation available, first agent year free
  • $99 annually with no renewal increase

Weak spots

  • The Limited Liability Company Annual Report filing is left to you
  • Serves Illinois only; other states need a separate agent
Visit IL Registered Agent.orgPartner link. We may earn money if you buy.
Read the IL Registered Agent.org review
No.2

Best yearly price

2. Illinois Registered Agent.co: best for companies based in Illinois

Score9.1out of 10
$99 a year, unchanged at renewal

Second grade, Illinois Registered Agent.co: an Illinois-focused agent at $99 a year, supplying an in-state street address for the registered office.

The company's registered office is an in-state street address supplied by Illinois Registered Agent.co; scans of served legal papers appear in your account.

IL Registered Agent.org and Illinois Registered Agent.co publish the same prices and plan features, so the grades are close and either is a sound pick.

What you get

  • A street address in the state, on the public record
  • Served legal documents are scanned and made available online

Good

  • Cheaper each year than Mainstay Filing
  • Forms LLCs as well, with year-one agent service included
  • $99 per year, same when it renews

Weak spots

  • The Limited Liability Company Annual Report filing is left to you
  • Serves Illinois only; other states need a separate agent
Visit Illinois Registered Agent.coPartner link. We may earn money if you buy.
Read the Illinois Registered Agent.co review
No.3

Best for multi-state companies

3. Mainstay Filing: best for all fifty states

Score9.0out of 10
$149 a year, unchanged at renewal

Third grade, Mainstay Filing: $149 per year for an agent that goes wherever the company goes, plus free scans of the first three government mailings each year.

A company still to be formed can use Mainstay's $199-a-year package, which files the Illinois paperwork and the annual report.

IL Registered Agent.org is $150 cheaper across three years, and that difference lowers Mainstay Filing's cost grade.

What you get

  • An in-state street address as the registered office
  • Papers served on the company scanned and uploaded the same business day, at no cost
  • Three government mailings a year scanned free
  • Compliance reminders

Good

  • $149 a year, no renewal increase
  • Three government mailings a year scanned at no cost
  • Open to LLCs, corporations, LPs, LLPs and nonprofits
  • Served papers scanned within the same business day, free

Weak spots

  • The agent alone costs $50 a year more than IL Registered Agent.org
  • You file annual reports yourself on the agent plan
Visit Mainstay FilingPartner link. We may earn money if you buy.
Read the Mainstay Filing review

Summary of the 3 grades

RankProviderGradePrice per yearRenewal priceBest fitSite
1IL Registered Agent.org9.3$99$99/yrThe lowest yearly price we rank hereVisit IL Registered Agent.orgPartner link. We may earn money if you buy.
2Illinois Registered Agent.co9.1$99$99/yrThe lowest yearly price we rank hereVisit Illinois Registered Agent.coPartner link. We may earn money if you buy.
3Mainstay Filing9.0$149$149/yrOne agent across fifty statesVisit Mainstay FilingPartner link. We may earn money if you buy.

The grades are editorial: Biz Formation Report assigns every mark out of 10 using the criteria on How we rank, not customer ratings.

Illinois registered agent prices, 2026: year one, renewal and three-year outlay

ProviderYear 1Year 2Year 3Three-year outlayRenewal at the same price
IL Registered Agent.org$99$99$99$297Yes
Illinois Registered Agent.co$99$99$99$297Yes
Mainstay Filing$149$149$149$447Yes

All prices were taken from the companies' own websites on November 12, 2026. Illinois's own fees are the same whichever agent is named.

Why the order falls this way

Of the grade, 32% rests on three-year bill and 32% on what the money buys; renewal handling, local rules match and pricing openness share the remaining 36%. Three-year bill decided Illinois.

Total outlay with IL Registered Agent.org over three years: $297, $150 less than Mainstay Filing. An agent needed only in Illinois gains little from fifty-state coverage, so the lower yearly price decided the grade.

Every criterion and weight is listed on How we rank.

Illinois registered agent rules according to Illinois Secretary of State (official)

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. Authority: 805 ILCS 180/1-35.

Illinois's Limited Liability Company Annual Report: cost, deadline and your agent

The Limited Liability Company Annual Report is due from every Illinois LLC every year, by before the first day of the entity's anniversary month. The state charges $75. A late filing adds $100. Related notices are mailed to your registered agent.

Illinois registered agent: common questions

Does an Illinois LLC have to maintain a registered agent?

Yes. The state expects every LLC to keep a registered agent on record, and Illinois requires that agent to have a street address inside its borders.

How much do Illinois registered agents charge per year?

Annual charges run from $99 to $149, and prices are unchanged at renewal.

Can the owner be the company's own registered agent?

Yes, provided you meet the state's requirements. An Illinois resident, or a business authorized to do business in Illinois. The LLC cannot act as its own agent.

What is the filing deadline for the Illinois Limited Liability Company Annual Report?

The deadline: before the first day of the entity's anniversary month. The state charges $75. Miss it and $100 is added.

Which registered agents does this report rank?

IL Registered Agent.org ($99 a year), Illinois Registered Agent.co ($99 a year) and Mainstay Filing ($149 a year), in descending order of grade.

What is the best-value registered agent in Illinois?

IL Registered Agent.org: $99 a year flat, with online scans of any legal papers served.

Keep reading

Source notes

  1. Illinois Secretary of State, Department of Business Services, Limited Liability Division (verified August 2026)
  2. Illinois Secretary of State, Department of Business Services, Limited Liability Division (verified August 2026)
  3. 805 ILCS 180/5-5 (verified August 2026)
  4. Illinois formation fee: Filing fee, official source (verified October 2026)
  5. Illinois formation fee: Filing fee, official source (verified October 2026)
  6. Illinois registered agent statute (verified October 2026)
  7. Pulled November 12, 2026: IL Registered Agent.org, pricing and service pages
  8. Pulled November 12, 2026: Illinois Registered Agent.co, pricing and service pages
  9. Pulled November 12, 2026: Mainstay Filing, Illinois service page