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Plain answers · Illinois

3 Best Registered Agents in Illinois (2026), Plainly Answered

Asked who to hire in Illinois in 2026, we'd say Illinois Registered Agent.co ($99 a year), IL Registered Agent.org ($99 a year) and Mainstay Filing ($149 a year), in that order. You will pay $99 to $149 for year one and $297 to $447 by year three.

By the Plain Charter editorial team ·

Answer in brief

Required?
Required by law
What the law calls it
Registered agent
Service price
$99 to $149 each year
Best picks
Illinois Registered Agent.co, IL Registered Agent.org then Mainstay Filing

The Illinois picks

Ranked by how we choose: three-year cost first, then what the price covers.
1We'd start here

1. Illinois Registered Agent.co: best for LLCs that stay in one state

$99 a year, renews at $99

Start with Illinois Registered Agent.co: it charges $99 a year, $99 at renewal, for an LLC that stays in Illinois.

It is the lower three-year cost of the two, which is what we weigh first.

The price covers

  • An office address in the state
  • Document scans online

Upsides

  • Lower yearly cost than Mainstay Filing
  • Flat $99 a year

What to weigh

  • Illinois only
  • Limited Liability Company Annual Report: your job
Visit Illinois Registered Agent.coPartner link. We may earn money if you buy.
2Local choice

2. IL Registered Agent.org: best for local service

$99 a year, renews at $99

IL Registered Agent.org is next: it charges $99 a year, $99 at renewal, for an LLC that stays in Illinois.

Same published prices as Illinois Registered Agent.co; pick whichever you prefer.

The price covers

  • An office address in the state
  • Document scans online

Upsides

  • Lower yearly cost than Mainstay Filing
  • Flat $99 a year

What to weigh

  • Illinois only
  • Limited Liability Company Annual Report: your job
Visit IL Registered Agent.orgPartner link. We may earn money if you buy.
3Most included

3. Mainstay Filing: best for owners planning to grow

$149 a year, renews at $149

Our number 3 is Mainstay Filing, since it costs $149 a year, $149 at renewal, and one account covers any state.

It costs $150 more than Illinois Registered Agent.co over three years, and cost carries the most weight with us.

The price covers

  • An in-state office address
  • Three government mailings a year scanned free
  • Covers LLCs, corporations, LPs, LLPs and nonprofits

Upsides

  • Flat $149 a year
  • Moves with the company

What to weigh

  • $50 a year more than Illinois Registered Agent.co
  • Agent service only, no report filing
Visit Mainstay FilingPartner link. We may earn money if you buy.

Prices together

#PickYear oneRenewal priceOver three yearsIncludes
1Illinois Registered Agent.co$99$99/yr$297an office address in the state; document scans onlineVisit Illinois Registered Agent.coPartner link. We may earn money if you buy.
2IL Registered Agent.org$99$99/yr$297an office address in the state; document scans onlineVisit IL Registered Agent.orgPartner link. We may earn money if you buy.
3Mainstay Filing$149$149/yr$447An in-state office address; three government mailings a year scanned free; Covers LLCs, corporations, LPs, LLPs and nonprofitsVisit Mainstay FilingPartner link. We may earn money if you buy.
Read from company pricing on November 12, 2026; three years means the first year plus two renewals.

Your questions

Does the law require a registered agent?

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

The law behind it: 805 ILCS 180/1-35. from ilga.gov · October 2026

Who qualifies?

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

An owner who qualifies may act as the agent at no cost.

How much per year?

$99 to $149 yearly. Over three years, $297 to $447.

Your choice of agent leaves state fees unchanged.

What is the agent for?

It is where lawsuits and state letters for the LLC land, in Illinois.

What matters most is that you hear about every document quickly. Read: service of process

What does the state charge yearly?

Mainly the Limited Liability Company Annual Report, once a year. Fee: $75. Deadline: before the first day of the entity's anniversary month.

from ilsos.gov · October 2026

Why this order?

Illinois Registered Agent.co wins on three-year cost, our 35% criterion.

The two biggest criteria are three-year cost and what the price takes off your plate, at 35% and 30%.

On cost, Illinois Registered Agent.co wins at $297 for three years, a $150 saving against Mainstay Filing.

See how we rank

What Illinois requires

RequirementWhat it isFrom
State filing fee$150from ilsos.gov · October 2026
Registered agentRequired by lawfrom ilga.gov · October 2026
Limited Liability Company Annual Report$75 every yearfrom ilsos.gov · October 2026
Paid to the state by year 3$300Total of these fees
We add the filing, two years of reports and any minimum tax for the three-year line. Publication and other variable costs are excluded.

More answers

May I name myself?

Usually yes: check the two rules above, who qualifies and the address.

What kind of address is required?

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.

What do the picks cost over three years?

Illinois Registered Agent.co $297, IL Registered Agent.org $297 and Mainstay Filing $447

Where do you get the fees?

Official schedules for state fees, company pricing for service fees, all dated on this page.

Does the state require a service?

No, you can file yourself if you meet the rules on this page.

Which one should I hire in Illinois?

Illinois Registered Agent.co, because $99 a year buys an in-state agent. Then IL Registered Agent.org and Mainstay Filing.

Where these answers come from

  1. Illinois Secretary of State, Department: ilsos.gov (August 2026)
  2. Illinois Secretary of State, Department: ilsos.gov (August 2026)
  3. 805 ILCS 180/5-5: ilga.gov (August 2026)
  4. Illinois formation fee: Filing fee: ilga.gov (October 2026)
  5. Illinois formation fee: Filing fee: ilsos.gov (October 2026)
  6. Illinois registered agent statute: ilga.gov (October 2026)
  7. Prices from the Illinois Registered Agent.co pricing page on November 12, 2026
  8. Prices from the IL Registered Agent.org pricing page on November 12, 2026
  9. Prices from the Mainstay Filing Illinois service page on November 12, 2026