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Keep it simple · Illinois

3 Best Registered Agents in Illinois (2026), Plainly

If you need registered agents in Illinois in 2026, we'd go with Mainstay Filing ($149 a year), IL Registered Agent.org ($99 a year) and Illinois Registered Agent.co ($99 a year), in that order. Budget $99 to $149 for the first year and $297 to $447 for three.
From the LLC Plainly editorial team

The short version

Mandatory?
Yes, it's required
The law calls it
Registered agent
Price of a service
$99 to $149 each year
Who we like
Mainstay Filing, IL Registered Agent.org then Illinois Registered Agent.co

Who we'd use in Illinois

The order comes from our five checks: three-year cost first, then how much the price covers.
Number one

1. Mainstay Filing: best for an agent that goes where you go

$149 a year, $149 when you renew

Why Mainstay Filing? Honestly, $149 a year is what it charges here and in every other state.

Going with IL Registered Agent.org saves $150 over three years, but only a Illinois company can use it.

Your money buys

  • An office address in the state
  • Free scans of three government mailings a year
  • Not just LLCs: corporations, LPs, LLPs and nonprofits as well

The good

  • Locked at $149 a year
  • One account works in every state

Trade-offs

  • Costs $50 a year more than IL Registered Agent.org
  • Reports aren't part of the agent plan
A Illinois favorite

2. IL Registered Agent.org: best for tight budgets

$99 a year, $99 when you renew

IL Registered Agent.org takes second, because it's $99 a year, $99 once you renew, for an LLC that stays in Illinois.

Your money buys

  • Your registered office address
  • Legal papers scanned and posted online

The good

  • Pay $99 a year with no change at renewal
  • A smaller yearly bill than Mainstay Filing

Trade-offs

  • You'd need another company in another state
  • You'll have to remember the Limited Liability Company Annual Report on your own
A Illinois favorite

3. Illinois Registered Agent.co: best for owners who like a local company

$99 a year, $99 when you renew

Illinois Registered Agent.co takes third, because it's $99 a year, $99 once you renew, for an LLC that stays in Illinois.

It charges what IL Registered Agent.org charges, so the order between them is close.

Your money buys

  • Your registered office address
  • Legal papers scanned and posted online

The good

  • A smaller yearly bill than Mainstay Filing
  • Pay $99 a year with no change at renewal

Trade-offs

  • You'd need another company in another state
  • You'll have to remember the Limited Liability Company Annual Report on your own

At a glance

#CompanyYear oneAfter year oneThree-year totalCovers
1Mainstay Filing$149$149/yr$447an office address in the state; free scans of three government mailings a year; Not just LLCs: corporations, LPs, LLPs and nonprofits as wellCheck out Mainstay FilingPartner link. We may earn money if you buy.
2IL Registered Agent.org$99$99/yr$297your registered office address; legal papers scanned and posted onlineCheck out IL Registered Agent.orgPartner link. We may earn money if you buy.
3Illinois Registered Agent.co$99$99/yr$297your registered office address; legal papers scanned and posted onlineCheck out Illinois Registered Agent.coPartner link. We may earn money if you buy.
These are service fees only, from each company's prices on November 13, 2026. The state's fees are the same whoever you pick.

What you probably want to know

Do I have to name a registered agent?

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

The rule comes from 805 ILCS 180/1-35. official: ilga.gov, October 2026

Who is allowed to be the agent?

An Illinois resident, or a business authorized to do business in Illinois. The LLC cannot act as its own agent.

Fit the rule and you can name yourself, which means no agent fee.

What will I pay an agent?

$99 to $149 per year, $297 to $447 over three years.

No state fee depends on which agent you pick.

What's the agent's role?

It collects lawsuits and official state mail for your LLC at an address in Illinois.

Service is only as good as the forwarding, so ask how documents reach you. A closer look at service of process

Are there yearly charges besides the agent?

Keep the Limited Liability Company Annual Report current. You file it every year for $75. The state lists the due date as before the first day of the entity's anniversary month, so don't let it slide.

official: ilsos.gov, October 2026

Why did the first pick win?

It's work taken off your hands (31% of the score), and Mainstay Filing does best there.

Together, cost across three years and work taken off your hands make up 64% of the score.

Add a state later and the same agent and price tag along; IL Registered Agent.org ends at the Illinois border.

See how we score

What Illinois wants

WhatAmount or ruleWhere we found it
What you pay to file$150official: ilsos.gov, October 2026
Registered agentYes, it's requiredofficial: ilga.gov, October 2026
Limited Liability Company Annual Report$75 every yearofficial: ilsos.gov, October 2026
Three-year state total$300Sum of the figures above
The last row is our own sum: the filing fee, the reports for years two and three and any minimum tax. Costs with no set price, like a newspaper notice, are left out.

Other things people ask

Do I have to pay for an agent?

Yes, as long as you fit the rule. Many owners still hire a service for privacy.

Which addresses does the state accept?

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.

After three years, what have I paid?

Mainstay Filing will cost you $447, IL Registered Agent.org will cost you $297, Illinois Registered Agent.co will cost you $297

What are the sources?

Every state fee links to its official page. Every service price is read from the company's own site.

Is hiring help required?

No. The state takes filings straight from owners. A service saves you time and can serve as your agent, but nobody makes you hire one.

Who do you like best in Illinois?

Mainstay Filing wins on work taken off your hands, ahead of IL Registered Agent.org and Illinois Registered Agent.co.

What we used for this page

  1. Illinois Secretary of State, Department (ilsos.gov), last confirmed August 2026
  2. Illinois Secretary of State, Department (ilsos.gov), last confirmed August 2026
  3. 805 ILCS 180/5-5 (ilga.gov), last confirmed August 2026
  4. Illinois formation fee: Filing fee (ilga.gov), last confirmed October 2026
  5. Illinois formation fee: Filing fee (ilsos.gov), last confirmed October 2026
  6. Illinois registered agent statute (ilga.gov), last confirmed October 2026
  7. Mainstay Filing Illinois service page, read November 13, 2026
  8. IL Registered Agent.org pricing page, read November 13, 2026
  9. Illinois Registered Agent.co pricing page, read November 13, 2026