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How to form an LLC in Illinois

File an Articles of Organization with the Illinois Secretary of State, Department of Business Services, Limited Liability Division. State filing fee $150.

Start my Illinois LLC → Search names on the state site ↗

Due to form

$150

State filing fee

How to file

Online or by mail

Online filings typically processed within days; standard mail longer; expedited within 24 hours.

Keeping it active

Annual Report

Before the first day of the LLC's anniversary month each year. · $75

The steps in Illinois

  1. 1

    Choose a name

    It must be distinguishable from other businesses on file and end with “Limited Liability Company”, “L.L.C.”, “LLC”. May not contain Corporation, Corp, Incorporated, Inc, Ltd, Co, Limited Partnership or L.P. Name reservation $25 for 90 days. You can reserve a name first for $25 (optional).

  2. 2

    Appoint a registered agent

    Individual resident of Illinois or a corporation/entity authorized in Illinois, with a registered office at an Illinois street address (no PO box alone).

  3. 3

    File the Articles of Organization

    File with the Illinois Secretary of State, Department of Business Services, Limited Liability Division (form LLC-5.5). You can file online or by mail. Illinois requires its own form or online system: LLCPros gives you a worksheet with every answer to copy in. Fee: $150.

  4. 4

    Sign an operating agreement

    Not filed with the state, and not required by Illinois law, but banks and partners often ask for one. LLCPros prepares one from your answers.

  5. 5

    Get an EIN and keep up with reports

    Get a free Employer Identification Number from the IRS, open a business bank account, then file the Annual Report (before the first day of the LLC's anniversary month each year.).

Fees

Filing fee — Articles of Organization$150
Optional: Expedited (24-hour) expedite+$100
Optional: name reservation$25
Later: Annual Report$75

$400 if the LLC has or may establish series; certificate of designation per series $50 (805 ILCS 180/50-10).

State taxes to know about

No franchise tax on LLCs. LLCs taxed as partnerships/S corps owe the 1.5% Personal Property Replacement Income Tax; corporate-taxed LLCs owe 2.5% replacement tax.

Questions about Illinois LLCs

›How much does it cost to form an LLC in Illinois?

The Illinois filing fee for the Articles of Organization is $150. Optional expedited processing costs more.

›What document forms an LLC in Illinois?

You file an Articles of Organization (form LLC-5.5) with the Illinois Secretary of State, Department of Business Services, Limited Liability Division.

›Does Illinois require a registered agent?

Yes. Individual resident of Illinois or a corporation/entity authorized in Illinois, with a registered office at an Illinois street address (no PO box alone).

›Does a Illinois LLC file an annual report?

Yes: the Annual Report, before the first day of the LLC's anniversary month each year., fee $75.

Double-check with the state

We could not confirm these on an official Illinois page when we last checked (November 12, 2026). Your filing plan lists them too.

  • When the annual (or biennial) report is due, and its fee
  • Expedited filing options and their fees
  • How long the state currently takes to process filings
  • The registered agent rules, including whether the agent must sign a consent
  • Which name endings and words the state allows
  • The link to the state’s business name search
  • The mailing address for paper filings
Self-help, not legal or tax advice. LLCPros is not a law firm, does not give legal or tax advice, and is not affiliated with any state or federal agency. We prepare documents from your answers and your state’s published rules; you file them and pay the state’s fees directly. Rules and fees change — check the official state links before filing, and talk to a lawyer or accountant about your situation.