LLC Review Desk's 2026 picks for LLC services in Illinois, favorite first, are Mainstay Filing ($199), IL Registered Agent.org ($199) and Illinois Registered Agent.co ($199). Mainstay Filing is our favorite, because for one yearly price of $199 you get the Illinois filing, registered agent service and the annual report, then $199 at renewal.
By the LLC Review Desk editorial team
Position 1
Our top pick in Illinois
1. Mainstay Filing: best for formation, agent and annual report in one simple price
$199 a year, and the state fee goes on top ($349 at checkout)
Our score
9.5out of 10
9.5 out of 10
Our favorite is Mainstay Filing, because the Illinois formation, your registered agent and the annual report all come in a single $199 price.
When your plan renews, Mainstay files the Limited Liability Company Annual Report for you. Illinois charges $75 every year for it, and the date is before the first day of the entity's anniversary month, and a late one costs $100 more. Mainstay passes the state's fee along at cost.
Over three years it costs $200 more than IL Registered Agent.org, and for us the extra things it handles are worth that.
In the price
Formation paperwork prepared and sent in
A full year as your registered agent
Your annual report, prepared and filed for you
Your EIN application, taken care of
What we like
Illinois's fee is passed through at cost
One yearly price of $199 that includes the annual report
Renews at $199, no add-ons
The EIN application is included
Trade-offs
After year one, its agent costs $100 a year more than IL Registered Agent.org's
2. IL Registered Agent.org: best for an Illinois LLC that will stay put
$199 to form, then $99 a year for the agent, with the state fee on top
Our score
9.2out of 10
9.2 out of 10
Coming in second is IL Registered Agent.org, because the Illinois formation costs $199 over the state's fee, with the registered agent free the first year, and keeping the agent is $99 a year.
You get a street address in the state for your registered office, and any papers served on the company are scanned into your online account.
The Limited Liability Company Annual Report isn't part of its published price, so you send it to Illinois yourself every year.
In the price
Formation prepared and filed
A first year as your registered agent
What we like
Year-two agent price: $99
Year-one registered agent service is covered
$199 to start the LLC, plus the filing fee
Trade-offs
Doesn't take care of the Limited Liability Company Annual Report
3. Illinois Registered Agent.co: best for a Illinois-only LLC
$199 to form, then $99 a year for the agent, with the state fee on top
Our score
8.9out of 10
8.9 out of 10
In third place is Illinois Registered Agent.co, because the Illinois formation costs $199 over the state's fee, with the registered agent free the first year, and keeping the agent is $99 a year.
You get a street address in the state for your registered office, and any papers served on the company are scanned into your online account.
The Limited Liability Company Annual Report isn't part of its published price, so you send it to Illinois yourself every year.
IL Registered Agent.org and Illinois Registered Agent.co share a price and a feature list, so you can't go wrong with either.
In the price
Formation prepared and filed
Your registered agent for year one
What we like
Year-one registered agent service is covered
$99 a year for the agent from year two
$199 covers the formation work; fees are extra
Trade-offs
Doesn't take care of the Limited Liability Company Annual Report
Our scores out of 10 are editorial: LLC Review Desk sets them using the criteria on How we rank. They aren't customer ratings.
What Illinois LLC services cost in 2026: year one, renewals and three years
Service
First year
Second year
Third year
Three-year total
Handles the Limited Liability Company Annual Report too
Mainstay Filing
$199
$199
$199
$597
Yes
IL Registered Agent.org
$199
$99
$99
$397
No
Illinois Registered Agent.co
$199
$99
$99
$397
No
We took each price from the company's own pages on November 12, 2026. On top of every row, Illinois charges a $150 filing fee, which isn't in these totals.
What decided the order
Two things count most to us, three-year cost and filings in the price, at 29% each. Renewal price, state fit and up-front totals share 42%, and Illinois came down to filings in the price.
In Illinois you'll need a report each year ($75 to the state), and sending it late adds $100. Mainstay's price includes that filing and IL Registered Agent.org's doesn't, which is why coverage beat IL Registered Agent.org's lower three-year cost.
You can read every criterion and weight on How we rank.
The Illinois LLC filing fee and form, from the state
Heads up: the Illinois Secretary of State takes $150 when you file the Articles of Organization (Form LLC-5.5). Every service below adds that fee at cost.
What a Illinois LLC needs after it is formed
There's one recurring item: the Limited Liability Company Annual Report, every year, by before the first day of the entity's anniversary month. The state asks for $75. A late filing adds $100. Every LLC must name a registered agent with an in-state street address.
Your questions about Illinois LLC services
How much does forming an LLC in Illinois set you back?
The state charges $150 to file, and services charge $199.
What paperwork makes the LLC official?
You send the Articles of Organization (Form LLC-5.5) to the Illinois Secretary of State.
Does the Illinois formation form ask me to name a registered agent?
Yes. You list a registered agent when you file and keep one on record, using a street address in Illinois.
Is there paperwork after the LLC is formed?
Yes, one item: the Limited Liability Company Annual Report. It comes every year, by before the first day of the entity's anniversary month, and the state asks $75.
Is the EIN included in the price?
With Mainstay Filing, yes; it comes with the yearly price. IL Registered Agent.org and Illinois Registered Agent.co tack on $99 for it. You can also ask the IRS for an EIN yourself, free of charge.
Who should I use to form my Illinois LLC?
Mainstay Filing, because $199 a year covers the Illinois formation, a year as your registered agent and the annual report, and it renews at $199.