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The Formation Desk

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

LLC service picks · Illinois

3 Best LLC Services in Illinois (2026)

The The Formation Desk call for LLC services in Illinois in 2026: IL Registered Agent.org ($199), Mainstay Filing ($199) and Illinois Registered Agent.co ($199), in that order. IL Registered Agent.org takes the call: Illinois formation for $199 on top of the state's fee, year-one agent included, then $99 a year to keep the agent.
Written by The Formation Desk editorial team
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Our top pick

1. IL Registered Agent.org: best for an Illinois LLC with no plans to expand

Form for $199; the agent is $99 a year after that, plus the state fee

Editorial score 9.5 out of 10

The desk picks IL Registered Agent.org: $199 to form, state fee extra, then $99 a year for the agent.

You get an in-state street address as the registered office, and papers served there are scanned into your account.

It leaves the Limited Liability Company Annual Report out of its prices, so you send that filing to Illinois yourself every year.

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

In the price

  • Illinois formation filed for you
  • A first year of registered agent service

Strengths

  • Then $99 a year for agent service
  • Forms the LLC for $199, plus the state's fee
  • Year-one registered agent service is in the price

Cons

  • No Limited Liability Company Annual Report filing included
  • EIN application will cost you $99 more
Visit IL Registered Agent.orgPartner link. We may earn money if you buy. IL Registered Agent.org up close
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All-in price

2. Mainstay Filing: best for formation, agent and annual report in a single price

$199 a year plus the state fee, $349 due at checkout

Editorial score 9.0 out of 10

Runner-up, Mainstay Filing: $199 a year gets you the Illinois formation, a year of registered agent service and the annual report, and it renews at $199.

Mainstay files the Limited Liability Company Annual Report for you when you renew. Illinois wants $75 every year, by before the first day of the entity's anniversary month, and a late filing tacks on $100; Mainstay hands the state's fee through at cost.

IL Registered Agent.org undercuts Mainstay Filing by $200 over three years, and that is why Mainstay sits lower on cost.

In the price

  • The formation document, filed on your behalf
  • Your registered agent, all year long
  • Annual report, filed by Mainstay
  • EIN application handled

Strengths

  • $199 on renewal, nothing extra
  • Illinois's fee passes through at cost
  • EIN application comes with the package
  • One $199 yearly price that takes in the annual report

Cons

  • Its agent renews at $100 a year more than IL Registered Agent.org
Visit Mainstay FilingPartner link. We may earn money if you buy. Mainstay Filing up close
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Best value here

3. Illinois Registered Agent.co: best for keeping it local in Illinois

Form for $199; the agent is $99 a year after that, plus the state fee

Editorial score 8.7 out of 10

Third, Illinois Registered Agent.co: $199 to form, state fee extra, then $99 a year for the agent.

You get an in-state street address as the registered office, and papers served there are scanned into your account.

It leaves the Limited Liability Company Annual Report out of its prices, so you send that filing to Illinois yourself every year.

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

  • Illinois formation filed for you
  • The first year as your registered agent

Strengths

  • Year-one registered agent service is in the price
  • Formation at $199 before state fees
  • The agent costs $99 after year one

Cons

  • No Limited Liability Company Annual Report filing included
  • EIN application will cost you $99 more
Visit Illinois Registered Agent.coPartner link. We may earn money if you buy. Illinois Registered Agent.co up close

The desk's 3 picks in brief

Pick Service Desk score Service fee Year two Good for Visit
1 IL Registered Agent.org 9.5 $199 $99/yr An Illinois-only LLC on a shoestring Visit IL Registered Agent.orgPartner link. We may earn money if you buy.
2 Mainstay Filing 9.0 $199 $199/yr Formation, agent and annual report in a single price Visit Mainstay FilingPartner link. We may earn money if you buy.
3 Illinois Registered Agent.co 8.7 $199 $99/yr An Illinois-only LLC on a shoestring Visit Illinois Registered Agent.coPartner link. We may earn money if you buy.

The scores out of 10 are the desk's own, drawn from the criteria on How we rank. They are not customer ratings.

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

Service Year one Year two Year three Bill over three years Limited Liability Company Annual Report filed on your behalf
IL Registered Agent.org $199 $99 $99 $397 No
Mainstay Filing $199 $199 $199 $597 Yes
Illinois Registered Agent.co $199 $99 $99 $397 No

Every price here was read off the company's own pages on November 12, 2026. Illinois's $150 filing fee comes on top of every row and is left out of these totals.

What tipped the order

The desk's method puts 33% on spend over three years and 33% on work the price removes, and 34% across what renewal looks like, fit with the state and plain price display. For Illinois, spend over three years did the deciding.

IL Registered Agent.org comes to $397 over three years, $200 less than Mainstay Filing. Mainstay would file the Limited Liability Company Annual Report too, but an owner can do that alone for just the state fee, so the lower price won.

The full criteria and weights are on How we rank.

Illinois LLC filing fee and form: the official numbers

It takes $150 to file the Articles of Organization (Form LLC-5.5) with the Illinois Secretary of State. Every service here adds that fee at cost on top of its own price.

After you form: keeping the Illinois LLC in order

Send in the Limited Liability Company Annual Report every year, by before the first day of the entity's anniversary month. It costs $75. Late means $100 extra. Every LLC must name a registered agent with an in-state street address.

Illinois LLC service: reader questions

What will setting up an LLC in Illinois cost you?

$150 goes to the state and $199 to the service.

What do you file to create the LLC?

The Articles of Organization (Form LLC-5.5), sent to the Illinois Secretary of State.

Does an Illinois LLC have to line up a registered agent on day one?

Yes. Illinois expects a registered agent from the start, with a street address inside the state.

What keeps coming due once an Illinois LLC exists?

One filing: the Limited Liability Company Annual Report, every year, due before the first day of the entity's anniversary month, costing $75.

Does the service price take care of the EIN?

Mainstay Filing builds it into the yearly price. IL Registered Agent.org and Illinois Registered Agent.co tack on $99. The IRS never charges for an EIN.

Who is our pick for an LLC service in Illinois?

IL Registered Agent.org, since $199 plus the Illinois filing fee, first-year registered agent service included, then $99 a year.

Keep reading

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. Mainstay Filing: Illinois service page, as of November 12, 2026
  9. Illinois Registered Agent.co: pricing and service pages, as of November 12, 2026