How to Start an LLC in Illinois (2026): Step by Step + 3 Best Services

To start an LLC in Illinois, file Articles of Organization (Form LLC-5.5) with the Illinois Secretary of State and pay $150. Best LLC services in Illinois (2026) 1. Mainstay Filing: $199/yr + state fee. Includes your Form LLC-5.5 filed, your EIN application, your registered agent every year and your annual report filed before your anniversary month. Renews at $199/yr. https://www.mainstayfiling.com/illino... 2. IL Registered Agent.org: $199 + state fee. Prepares and files your Articles of Organization, with the first year of registered agent service free, then $99/yr. https://www.ilregisteredagent.org/llc... 3. Illinois Registered Agent.co: $199 + state fee. Forms your Illinois LLC with the first year of registered agent service free, then $99/yr. https://www.illinoisregisteredagent.c... How to start an LLC in Illinois, step by step 00:00 How to start an LLC in Illinois 00:31 Step 1: Choose a name 00:57 Step 2: Name a registered agent 01:23 Step 3: File Articles of Organization ($150) 01:58 Step 4: Write an operating agreement 02:20 Step 5: Get a free EIN 02:48 Step 6: File the annual report ($75) 03:16 What it costs 03:28 3 best ways to file: #1 Mainstay Filing 04:10 #2 IL Registered Agent.org 04:29 #3 Illinois Registered Agent.co 05:01 Recap Illinois LLC facts (checked October 7, 2026) Filing: Articles of Organization, Form LLC-5.5, $150 (805 ILCS 180/50-10), online or by mail in duplicate. Standard online processing 10 business days; 24-hour service $250 in all. Name: must include "limited liability company," "LLC" or "L.L.C."; no "Corporation," "Corp.," "Incorporated," "Inc.," "Ltd.," "Co.," "Limited Partnership" or "L.P."; reservation $25 for 90 days. Registered agent: an Illinois resident or a business authorized in Illinois, at an Illinois street address (not a P.O. box alone); the LLC can't be its own agent. Change later: $25. Operating agreement: may be oral, in a record or implied; not filed with the state. EIN: free from the IRS at IRS.gov. Annual report: $75, before the first day of the LLC's anniversary month every year. Penalty $100 plus $100 a year from the second year if still missing; after a notice, dissolution if not corrected within 120 days. No beneficial ownership (BOI) report for U.S. companies (FinCEN). Official sources Illinois Secretary of State, LLC filing: https://www.ilsos.gov/departments/bus... Form LLC-5.5, Articles of Organization (PDF): https://www.ilsos.gov/content/dam/pub... 805 ILCS 180/50-10 (fees): https://www.ilga.gov/legislation/ilcs... 805 ILCS 180/1-10 (names): https://www.ilga.gov/legislation/ilcs... 805 ILCS 180/50-15 (annual report penalty): https://www.ilga.gov/legislation/ilcs... IRS, Get an EIN: https://www.irs.gov/businesses/small-... FinCEN, BOI: https://www.fincen.gov/boi General information, not legal advice. Prices and fees as of October 7, 2026.