Illinois Registered Agent Guide (2026): Rules, Fees and the 3 Best Agents
In 2026 we'd hire IL Registered Agent.org ($99 a year), Mainstay Filing ($149 a year) and Illinois Registered Agent.co ($99 a year) for registered agent service in Illinois, in that order. Illinois requires a registered agent for every LLC. Yearly state fees run $75, which ranks 34th of 50.
State Filing Data research desk
Illinois fee data
34th
12550
of 50, yearly state fees
Rank 1 is the least expensive state, shared rank. Full table
Every LLC must name a registered agent with an in-state street address. 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.
Who can serve: An Illinois resident, or a business authorized to do business in Illinois. The LLC cannot act as its own agent. 805 ILCS 180/1-35 sets this out.
What Illinois charges each year
Besides the agent, the LLC files the Limited Liability Company Annual Report every year for $75, due before the first day of the entity's anniversary month. Late filings cost $100.
Why this order
The split between IL Registered Agent.org and Mainstay Filing sits in service fees over three years, which carries 35%.
At $297 over three years, $150 below Mainstay Filing, IL Registered Agent.org leads on cost.
Illinois questions answered
Does Illinois require a registered agent?
Yes. Every LLC must name a registered agent with an in-state street address.
Who can serve as the registered agent?
An Illinois resident, or a business authorized to do business in Illinois. The LLC cannot act as its own agent.
How much does a registered agent cost in Illinois?
$99 to $149 a year among our picks.
What does the LLC pay the state each year?
$75 a year on our measure: the Limited Liability Company Annual Report ($75 every year).
Which registered agents are on this page?
IL Registered Agent.org ($99 a year), Mainstay Filing ($149 a year) and Illinois Registered Agent.co ($99 a year), in our order.
Which registered agent would you pick?
We'd use IL Registered Agent.org: $99 a year, the same at renewal, for a company that operates in one state. Mainstay Filing and Illinois Registered Agent.co follow.