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The Formation Desk

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

Registered agent picks · Illinois

3 Best Registered Agents in Illinois (2026)

The The Formation Desk call for registered agents in Illinois in 2026: 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 takes the call: $99 a year, holding on renewal, the lowest yearly price on this list.
Written by The Formation Desk editorial team
1
Our top pick

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

$99 a year, and it holds on renewal

Editorial score 9.4 out of 10

The desk picks IL Registered Agent.org: an Illinois specialist at $99 a year, with an in-state street address as the registered office.

IL Registered Agent.org puts an in-state street address on file for the company and scans served legal papers into your account.

Three years of service run cheaper here than at Mainstay Filing, and cost carries big weight.

In the price

  • An in-state street address for the registered office
  • Everything served on the company is scanned for you

Strengths

  • $99 yearly, renewing at the same price
  • Comes in under Mainstay Filing every year
  • LLC formation available, year-one agent included

Cons

  • The Limited Liability Company Annual Report is your job
  • Illinois only; you need another agent elsewhere
Visit IL Registered Agent.orgPartner link. We may earn money if you buy. IL Registered Agent.org up close
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Best local option

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

$99 a year, and it holds on renewal

Editorial score 9.1 out of 10

Runner-up, Illinois Registered Agent.co: an Illinois specialist at $99 a year, with an in-state street address as the registered office.

Your registered office is an in-state street address from Illinois Registered Agent.co, and legal papers served on the company are scanned for you.

IL Registered Agent.org and Illinois Registered Agent.co list the same prices and plan features, so it is close and either one works.

In the price

  • An in-state street address for the registered office
  • Everything served on the company is scanned for you

Strengths

  • A lower yearly price than Mainstay Filing
  • Forms LLCs too, with the first agent year free
  • $99 per year and no bump at renewal

Cons

  • The Limited Liability Company Annual Report is your job
  • Illinois only; you need another agent elsewhere
Visit Illinois Registered Agent.coPartner link. We may earn money if you buy. Illinois Registered Agent.co up close
3
One agent, every state

3. Mainstay Filing: best for every state

$149 a year, and it holds on renewal

Editorial score 8.9 out of 10

Third, Mainstay Filing: $149 for a single agent plan that works in every state, $149 on renewal.

Haven't formed yet? Mainstay's $199-a-year package handles the Illinois filing and the annual report.

IL Registered Agent.org undercuts Mainstay Filing by $150 over three years, and that is why Mainstay sits lower on cost.

In the price

  • A real in-state address as the registered office
  • Free scans of service of process, uploaded the same business day
  • The first three pieces of government mail each year scanned at no charge
  • Compliance reminders

Strengths

  • Works for LLCs, corporations, LPs, LLPs and nonprofits alike
  • Free scans of served papers on the same business day
  • First three government mailings each year, scanned free
  • $149 a year and it holds on renewal

Cons

  • $50 a year more than IL Registered Agent.org for agent service alone
  • Only the formation package files annual reports
Visit Mainstay FilingPartner link. We may earn money if you buy. Mainstay Filing up close

The desk's 3 picks in brief

Pick Service Desk score Price a year Renewal Good for Visit
1 IL Registered Agent.org 9.4 $99 $99/yr The lowest yearly price we rank here Visit IL Registered Agent.orgPartner link. We may earn money if you buy.
2 Illinois Registered Agent.co 9.1 $99 $99/yr The lowest yearly price we rank here Visit Illinois Registered Agent.coPartner link. We may earn money if you buy.
3 Mainstay Filing 8.9 $149 $149/yr One agent that covers every state Visit Mainstay FilingPartner link. We may earn money if you buy.

A score out of 10 here is editorial judgment built on the criteria explained on How we rank, not an average of customer ratings.

What a Illinois registered agent costs in 2026: year one, renewal and the three-year bill

Service Year one Year two Year three Bill over three years Price holds on renewal
IL Registered Agent.org $99 $99 $99 $297 Yes
Illinois Registered Agent.co $99 $99 $99 $297 Yes
Mainstay Filing $149 $149 $149 $447 Yes

Every price here was read off the company's own pages on November 12, 2026. Illinois charges the same state fees whichever agent you name.

Why it falls this way

Here is the weighting: 33% for spend over three years, 33% for work the price removes, 34% spread over what renewal looks like, fit with the state and plain price display. In Illinois, spend over three years made the call.

IL Registered Agent.org comes to $297 over three years, $150 less than Mainstay Filing. If Illinois is your only state, fifty-state coverage does little for you, and the lower yearly price wins.

The full criteria and weights are on How we rank.

Illinois registered agent rules straight from 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. The law behind it: 805 ILCS 180/1-35.

Illinois's Limited Liability Company Annual Report: what it costs, when it is due, who gets the notice

Illinois LLCs send in the Limited Liability Company Annual Report every year, due before the first day of the entity's anniversary month. The state's fee is $75. Send it late and $100 gets added. Notices about it land with your registered agent.

Illinois registered agent: reader questions

Do you need a registered agent to run an Illinois LLC?

You do. Illinois wants a registered agent on file for every LLC, and the agent must have a street address in the state.

What should you expect to pay a Illinois registered agent?

Plan on $99 to $149 a year, and the price holds when it renews.

Could you serve as your own registered agent?

You can if the state's rules allow it. An Illinois resident, or a business authorized to do business in Illinois. The LLC cannot act as its own agent.

When does the Illinois Limited Liability Company Annual Report have to go in?

Get it in by before the first day of the entity's anniversary month. The state's cut is $75. Miss the date and it costs $100 more.

Which registered agents did the desk rank here?

IL Registered Agent.org ($99 a year), Illinois Registered Agent.co ($99 a year) and Mainstay Filing ($149 a year), best pick first.

Who is our pick for registered agent in Illinois?

IL Registered Agent.org, since $99 a year flat, with scans of served legal papers sent to your account.

Related pages

Where the numbers came from

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