How Long Does It Take To Form an LLC in Illinois (Guide)

Jon Morgan
Published by Jon Morgan | Co-Founder & Chief Editor
Last updated: January 16, 2026
Methodology
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Before your LLC can benefit from a limited liability company structure, it is important to note that there is a turnaround time for the SOS to receive, verify and finally approve your application.

Over my 7+ years as a Mergers and Acquisitions specialist, I've personally facilitated LLC formations for 20 businesses across Illinois, with processing times ranging from 24 hours to 4 weeks depending on the filing method chosen.

After analyzing formation data from 50+ Illinois LLCs and consulting directly with an Illinois LLC attorney, I identified the exact factors that determine approval timelines.

I've also made costly mistakes—including a $150 refiling fee after submitting incomplete documents via mail—that I'll help you avoid.

Quick Summary

  • It takes 7-14 business days to form an LLC in Illinois via mail and 5-10 business days if filed online.
  • The Illinois Secretary of State offers an expedited shipping option for LLC owners at an additional fee of $100 for 24-hour processing.
  • Illinois generated a net increase of 14,131 small business jobs between March 2023 and March 2024, according to the US Small Business Administration. The ability to establish an LLC within a single business day means you can start operating faster than in 38 other states.
  • Whenever my clients file their applications, I advise them to submit online using the expedited option.
Not sure which LLC is right for you? Let us help.


What is The Fastest Way to Start an LLC in Illinois?

A person doing work to form an LLC in Illinois

The fastest way to start an LLC in Illinois is by filing online or in person using the expedited service at an additional cost. Your formation documents are processed within 24 hours.

If you want your business to be operational at the soonest possible time, this is the best option for your LLC.

LLC Processing Time in Illinois

The Illinois Secretary of State offers different processing times for the articles of organization depending on the LLC owner's filing method.

Here are four filing methods offered by the Secretary of State's office in Illinois and their different LLC processing times.

1. Expedited Illinois LLC Processing Time Online and In Person (24-hour processing + $100)

A person filing paperwork online

The Illinois SOS offers a 24-hour expedited shipping option for an additional $100 state fee.

When I was about to file for a series LLC, I learned that the payment for expedited service costs more.

If you're filing your LLC legal documents online and opting for expedited service, you'll pay $250 for limited liability companies and $500 for series LLCs.

2. Non-Expedited Illinois LLC Processing Time By Mail (7-14 business days)

A person filing paperwork by mail

The non-expedited processing for all mail submissions takes 7-14 business days, excluding holidays and weekends, plus additional mailing time. You cannot request expedited processing via mail; you must visit the office in person or file online to access expedited options.

To file by mail, I had to download Form LLC-5.5 from the Illinois Secretary of State website, fill it out, and send it to the following address:

Central Registration Division Illinois Department of Revenue
PO BOX 19030
SPRINGFIELD IL 62794-9030

Total approval time for mail filings typically ranges from 3-4 weeks when accounting for both processing and transit time.

3. Illinois LLC Processing Time Online (5-10 business days)

Online filing for domestic and foreign LLCs in Illinois is processed within 5-10 business days for non-expedited options. You can register online through the MyTaxIllinois website [1, 2].

When a client had to file articles of organization online, I reminded them to have all LLC information on hand so they won't experience website time-outs.

The SOS has built an automatic time-out security feature that occurs after every 30 minutes of inactivity.

Also, avoid filing on Sundays between 3:00 AM and 6:00 AM CST as there is scheduled website maintenance and, as a result, slow response times.

“Don't forget, the LLC formation timeframe is just one piece of the puzzle. Building a strong operating agreement and obtaining any necessary licenses are crucial next steps.”

Delina Yasmeh, J.D./Tax LL.M, Distinguished Expert in Mergers & Acquisitions

Factors Influencing The Formation Timeline Of Illinois LLCs

A person writing down on a clipboard

Although the Illinois Secretary of State has an established formation timeline, various factors can prolong the approval time. This includes the following:

  • Filing method: The primary factor that affects the approval time of your LLC is the filing method you opted for. Mail, online and expedited options have varying processing periods.
  • Processing errors: Website downtime and equipment malfunctions can prolong the approval time.
  • Documentation issues: Lack of information or inaccurate details may cause your application to be rejected. The need to refile would cause a delay in the formation of your LLC.

Despite possible delays, the conducive business climate in Illinois has resulted in the launch of 14,131 new establishments from March 2023 to March 2024, according to the US Small Business Administration.

FAQs

Where Can I Check the Status of My Illinois LLC Formation During the Processing Period?

You can check the status of your Illinois LLC formation during the processing period by using your Packet Number that has been assigned by the Secretary of State.

Is There a Difference in Processing Time for Domestic and Foreign LLCs in Illinois?

There is a difference in processing time for domestic and foreign LLCs in Illinois. The state takes up to 45 days to review and approve Foreign limited liability companies.

What Do I Need After My Illinois LLC Is Approved?

After your Illinois LLC is approved, you may need a federal employer identification number from the IRS (10-15 minutes online), registration with the Illinois Department of Revenue for your business tax ID (2-3 business days), and industry-specific business licenses depending on your location and activities.

References:

  1. https://tax.illinois.gov/businesses/registration.html
  2. https://www.ilsos.gov/departments/business_services/organization/llc_instructions.html

About The Author

Co-Founder & Chief Editor
Jon Morgan, MBA, LLM, has over ten years of experience growing startups and currently serves as CEO and Editor-in-Chief of Venture Smarter. Educated at UC Davis and Harvard, he offers deeply informed guidance. Beyond work, he enjoys spending time with family, his poodle Sophie, and learning Spanish.
Learn more about our editorial policy
Growth & Transition Advisor
LJ Viveros has 40 years of experience in founding and scaling businesses, including a significant sale to Logitech. He has led Market Solutions LLC since 1999, focusing on strategic transitions for global brands. A graduate of Saint Mary’s College in Communications, LJ is also a distinguished Matsushita Executive alumnus.
Learn more about our editorial policy

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5 thoughts on “How Long Does It Take To Form an LLC in Illinois (Guide)

  1. Everything is very open with a clear explanation of the challenges. It was really informative. Your site is very useful. Thank you for sharing!

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  3. Great post. I used to be checking constantly this blog and I am inspired! Extremely useful information specifically the remaining phase 🙂 I handle such information much. I was looking for this certain information for a long time. Thank you and best of luck.

  4. Thank you Jon for outlining the timeline so clearly. I wasn’t sure how long I’d be waiting for my LLC to be approved. This will help a lot.

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