3 Best Registered Agents in Illinois (2026): The Straight Story
Our 2026 ranking of registered agents in Illinois runs Mainstay Filing ($149 a year), IL Registered Agent.org ($99 a year) and Illinois Registered Agent.co ($99 a year). Year one's $99 to $149. Three years come to $297 to $447.
Straight from the LLC Straight Talk editorial team
Quick facts
The short of it
Do you have to?
Yes, it's the law
Statute's word
Registered agent
Going rate
$99 to $149 a year
Our pick
Mainstay Filing, IL Registered Agent.org then Illinois Registered Agent.co
Service fees only, from each company's prices on November 13, 2026. State fees are the same whoever you pick.
The questions that matter
Does the state make me have a registered agent?
Every LLC must name a registered agent with an in-state street address.
The law: 805 ILCS 180/1-35. ilga.gov, confirmed October 2026, if you don't believe us
Who can be the agent?
An Illinois resident, or a business authorized to do business in Illinois. The LLC cannot act as its own agent.
A qualifying owner can serve for free.
What's the going rate for an agent?
Agent prices on this page start at $99 to $149 a year, and three years of service come to $297 to $447.
No state fee depends on your choice of agent.
Why does the state want one?
Court papers and state notices for your company get delivered to its Illinois address.
Ask how fast the agent tells you when something shows up, so you don't blow a deadline. What's service of process?
Anything due annually?
You'll file the Limited Liability Company Annual Report every year, and it's $75 each time. Here's the date the state gives: before the first day of the entity's anniversary month. Don't miss it.
ilsos.gov, confirmed October 2026, if you don't believe us
What put number one on top?
Mainstay Filing scores best on jobs the price actually covers, and that test is worth 30%.
We run five tests: money out the door in three years (35%), jobs the price actually covers (30%), no hunting for the price (14%), no surprise at renewal (11%) and where it works (10%).
Only the first pick works in all fifty states, and that matters the day you register somewhere else.
ilsos.gov, confirmed October 2026, if you don't believe us
Registered agent
Yes, it's the law
ilga.gov, confirmed October 2026, if you don't believe us
Limited Liability Company Annual Report
$75 every year
ilsos.gov, confirmed October 2026, if you don't believe us
What the state collects in three years
$300
Our sum of the rows above
Want to check the total? Add the filing fee, the next two reports and any minimum tax. We don't count costs without a set amount.
Still wondering?
Can I be my own agent?
Usually. If you fit the state's rule on who qualifies and which address counts, go ahead.
Which addresses count?
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?
Mainstay Filing will set you back $447, and IL Registered Agent.org will set you back $297, and Illinois Registered Agent.co will set you back $297
Where do these numbers come from?
Each state fee links to its official page, and each service price comes from the company's own site.
Do I have to use a service?
No law says you need a service. It's a convenience you pay for.
Who should I use for a registered agent in Illinois?
Mainstay Filing is first: $149 a year goes with you when the company adds a state. Then comes IL Registered Agent.org and Illinois Registered Agent.co.