Illinois LLC Formation: Requirements & Steps

Navigate Illinois LLC formation requirements with our comprehensive guide. Learn about naming, registered agents, filing, EINs, and ongoing compliance for your IL business.

Quick Answer: Forming an LLC in Illinois

Forming an Illinois LLC involves these key steps with the Illinois Secretary of State (SOS):

Verify business name availability via the IL SOS name search.
Appoint a registered agent with a physical Illinois address.
File Articles of Organization (Form LLC-5.5) with the IL SOS; pay the $150 fee.
Obtain a federal Employer Identification Number (EIN) from the IRS (no cost).
Draft an Operating Agreement (internal document, not state-filed).
File an Initial Report with the IL SOS within 60 days of formation.

The Illinois Limited Liability Company Act (805 ILCS 180/) governs this process. Detailed requirements follow.

Step-by-Step Illinois LLC Formation Requirements

Name Availability Search

Verify your chosen name is available via the IL SOS Business Services division's free online database at ilsos.gov. If available but not ready to file, you can reserve the name (see Name Reservation).

Appointing a Registered Agent

Illinois LLCs must continuously maintain a registered agent in the state (805 ILCS 180/1-35). The agent receives legal documents, service of process, and official state correspondence. Requirements include:

Must have a physical street address in Illinois (no P.O. boxes).
Must be available during normal business hours.
Can be an individual member, a manager, or a commercial registered agent service.

Promptly update the IL SOS if your registered agent changes. Failure to maintain an agent can result in bad standing.

Filing Articles of Organization (Form LLC-5.5)

File Form LLC-5.5 with the Illinois Secretary of State, Business Services Department, to legally create your LLC. The form requires:

LLC name (including the required designator).
Principal place of business address.
Registered agent name and address.
Name and address of each organizer.
Whether the LLC is member-managed or manager-managed.
Effective date (if not immediate).

The filing fee is $150 (Illinois Secretary of State Fee Schedule). File online at ilsos.gov, by mail, or in person at the Springfield or Chicago SOS offices.

Operating Agreement

Illinois does not require filing an Operating Agreement with the state, but the Illinois Limited Liability Company Act (805 ILCS 180/15-5) contemplates its existence. This internal document governs:

Member ownership percentages and capital contributions.
Profit and loss allocation.
Voting rights and decision-making procedures.
Rules for adding or removing members.
Dissolution procedures.

Without an Operating Agreement, your LLC defaults to statutory rules (805 ILCS 180/), which may not align with member preferences. Banks and investors typically request this document.

Initial Report

Illinois LLCs must file an Initial Report with the IL SOS within 60 days of Articles of Organization approval. This report confirms the registered agent and principal office address. Consult the Illinois Secretary of State Business Services division for current fees and forms.

Naming Your Illinois LLC and Registered Agent Rules

LLC Naming Requirements

Your LLC name must comply with 805 ILCS 180/1-10. Key rules:

The name must include "Limited Liability Company," "L.L.C.," or "LLC" as the last words.
The name must be distinguishable from other business entities already on file with the IL SOS.
Certain words are restricted or prohibited, including terms that imply a government agency (e.g., "FBI," "Treasury") or regulated professions (e.g., "Bank," "Insurance") without proper authorization.
Names cannot be deceptively similar to existing registered entities.

Name Reservation

To reserve a name before filing, submit an Application to Reserve a Name (Form LLC-1.15) with the IL SOS. The reservation lasts 90 days and costs $25 (Illinois Secretary of State Fee Schedule). File online or by mail. Reservation holds the name; it does not create the LLC.

Registered Agent Rules

The registered agent requirement (805 ILCS 180/1-35) includes these practical points:

An individual member can serve as their own registered agent, but their address becomes part of the public record.
Commercial registered agent services typically charge $50 to $300 per year (varies by provider).
If using a commercial service, confirm they are authorized to do business in Illinois.
The registered agent must consent to the appointment, either in writing or by signing the Articles of Organization.

The registered agent's address is where the state sends legal notices. An unreachable registered agent can lead to missed legal deadlines, including those for lawsuits.

Federal and Illinois Tax ID Requirements for LLCs

Employer Identification Number (EIN)

An EIN is your LLC's federal tax identification number, issued by the IRS at no cost. Apply using IRS Form SS-4, either online at irs.gov (instant issuance) or by mail (takes several weeks).

You are required to obtain an EIN if your LLC:

Has more than one member (multi-member LLC).
Has or plans to hire employees.
Elects to be taxed as a corporation.

Single-member LLCs with no employees can technically use the owner's Social Security Number, but most banks require an EIN to open a business account. Obtaining an EIN is free and takes minutes online (IRS Form SS-4 instructions).

IRS Default Tax Classification

The IRS classifies LLCs by default based on structure (IRS Form 8832 instructions):

LLC Type	Default Federal Tax Treatment
Single-member LLC	Disregarded entity (taxed on owner's personal return)
Multi-member LLC	Partnership (files Form 1065)

Electing Corporate Tax Status

If the default classification is unsuitable, options include:

C-corporation election: File IRS Form 8832 to be taxed as a C-corp.
S-corporation election: File IRS Form 2553 (LLC must first be eligible under IRS S-corp rules).

Illinois generally follows federal entity classification for state income tax purposes, unlike states such as California, Tennessee, New Hampshire, or Texas, which tax LLCs as corporations regardless of federal election. Consult a CPA before making a tax election due to long-term consequences.

Illinois State Tax Registrations

Beyond the EIN, registration with the Illinois Department of Revenue (IDOR) may be required for:

Illinois Business Tax (IBT) number: Required if you collect sales tax, have employees, or owe Illinois income tax withholding. Register at mytax.illinois.gov.
Sales tax permit: Required if you sell taxable goods or certain services in Illinois (IDOR website).
Withholding tax registration: Required if you have Illinois employees (IDOR website).

IDOR registration occurs via MyTax Illinois. Consult the Illinois Department of Revenue directly at tax.illinois.gov for current registration requirements and forms.

Ongoing Compliance and Annual Requirements for Illinois LLCs

Annual Report

Illinois LLCs must file an Annual Report with the IL SOS each year (805 ILCS 180/50-1). Key details:

Due date: The first day of the LLC's anniversary month each year (the month your Articles of Organization were approved).
Filing fee: $75 for standard domestic LLCs (Illinois Secretary of State Fee Schedule).
What it covers: Confirms or updates your registered agent, principal office address, and member/manager information.

Late filing results in penalties and can eventually lead to administrative dissolution. File online at ilsos.gov to avoid mail delays.

Operating Agreement Maintenance

Maintain your Operating Agreement by updating it when membership, ownership percentages, or management structure changes. An outdated agreement can lead to disputes and complicate banking, financing, or business sale.

Business Licenses and Permits

Illinois does not issue a single statewide general business license. Depending on industry and location, you may need:

State professional licenses (consult the Illinois Department of Financial and Professional Regulation, IDFPR, at idfpr.illinois.gov).
City or county business licenses (varies by jurisdiction; contact your local municipality directly).
Industry-specific permits (food service, construction, childcare, etc.).

No single lookup exists for all permits. Begin with your city or county clerk's office and the IDFPR for licensed professions.

Ongoing Tax Obligations

Recurring filings include:

Federal income tax return (Form 1065 for partnerships, Schedule C or E for disregarded entities, or corporate return if elected).
Illinois Personal Property Replacement Tax (LLCs taxed as partnerships pay 1.5% on net income; consult IDOR for current rates).
Illinois sales tax returns if registered (frequency varies by revenue volume, per IDOR).
Payroll tax deposits and returns if you have employees (IRS and IDOR).

Illinois LLC Formation Fees and Timelines: A Comparison

Fee Summary

Filing	Fee
Articles of Organization (Form LLC-5.5)	$150
Annual Report	$75
Name Reservation (Form LLC-1.15)	$25
Expedited processing (24-hour)	$100 additional
Expedited processing (same-day)	$200 additional

Source: Illinois Secretary of State Fee Schedule. Verify current fees at ilsos.gov before filing, as the SOS can update the schedule.

Processing Times

Standard mail filings with the IL SOS typically take several weeks. Online filings are generally faster. Expedited options include:

24-hour expedited: $100 surcharge on top of the base filing fee.
Same-day expedited: $200 surcharge (must be submitted by a specific cutoff time; consult the IL SOS for current cutoff hours).

Processing times may extend during high-volume periods. If your formation date is critical, use expedited filing or file online.

Additional Costs to Budget

Registered agent service: varies by provider, typically $50 to $300 per year.
Attorney fees for Operating Agreement drafting: varies by jurisdiction and complexity.
CPA fees for tax setup and annual filings: varies by jurisdiction.
Local business licenses and permits: varies by jurisdiction.
IDFPR professional licenses: varies by license type.

Federal Tax Considerations

The federal tax treatment of LLCs varies based on the number of members. A single-member LLC is treated as a disregarded entity under IRC § 7701, while a multi-member LLC is classified as a partnership under IRC § 761. Additionally, LLCs can elect S-corporation status via Form 2553, which can impact self-employment tax liabilities.

Single-member LLCs report income on Schedule C, while multi-member LLCs file Form 1065 and issue K-1s to members.
Self-employment tax applies to active LLC income at a rate of 15.3% up to the Social Security wage base.
LLCs may qualify for the Qualified Business Income deduction under IRC § 199A, allowing a deduction of up to 20% of qualified pass-through income, subject to certain income thresholds and rules regarding specified service trades or businesses (SSTBs).
Form 2553 must be filed within a specific timeframe to elect S-corporation status, which can change how income is taxed.
Be aware of potential state-level conformity issues in Illinois; verify with a state CPA regarding how federal provisions apply at the state level.

This is not tax advice — consult a CPA familiar with LLC formation for your specific situation.

Frequently Asked Questions

What is the total cost to form an LLC in Illinois?

The total cost to form an LLC in Illinois includes a $150 filing fee for the Articles of Organization. Additionally, you should budget for any potential costs related to drafting an Operating Agreement and maintaining your registered agent.

How long does it take to form an LLC in Illinois?

The processing time for filing the Articles of Organization can vary, but it typically takes a few business days if filed online. However, if you file by mail, it may take longer.

Who should I contact if I have questions about forming my LLC in Illinois?

For questions regarding LLC formation, you can contact the Illinois Secretary of State's Business Services division directly through their website or by phone for assistance.

What are common mistakes to avoid when filing for an LLC in Illinois?

Common mistakes include failing to ensure the chosen LLC name is distinguishable from existing entities and not appointing a registered agent with a physical Illinois address. Additionally, neglecting to file the Initial Report within 60 days can lead to penalties.

Are there any exemptions for LLC formation in Illinois?

There are no specific exemptions for forming an LLC in Illinois; all businesses must follow the same formation process. However, certain business types may have additional licensing or regulatory requirements.

Next Steps: Who to Contact for Illinois LLC Assistance

Illinois Secretary of State

The SOS Business Services Department handles LLC formation filings, name searches, annual reports, and status inquiries.

Website: ilsos.gov
Springfield office: 501 S. Second St., Springfield, IL 62756
Chicago office: 69 W. Washington St., Suite 1240, Chicago, IL 60602
Phone: Consult the SOS website for current department numbers, as lines are division-specific.

Contact the SOS for: Articles of Organization, name availability, Annual Report filing, registered agent changes, and certificate of good standing requests.

Illinois Department of Revenue

The IDOR handles state tax registrations and filings.

Website: tax.illinois.gov
MyTax Illinois portal: mytax.illinois.gov (for online registration and filing).
Phone: Consult the IDOR website for current taxpayer assistance numbers.

Contact the IDOR for: IBT number registration, sales tax permits, withholding tax registration, and Illinois income tax questions.

IRS (Federal Tax Matters)

EIN application: irs.gov/businesses/small-businesses-self-employed/apply-for-an-employer-identification-number-ein-online
Form SS-4, Form 8832, Form 2553: Available at irs.gov.
IRS Business and Specialty Tax Line: Consult irs.gov for current contact numbers.

Legal Professionals

An attorney familiar with Illinois business law can draft or review your Operating Agreement, advise on liability protection, and assist with complex ownership structures. The Illinois State Bar Association (isba.org) has a lawyer referral service.

Accounting Professionals

A CPA can advise on tax classification, set up bookkeeping, and handle annual filings. The Illinois CPA Society (icpas.org) maintains a directory of members.

Local Government Offices

For city or county business licenses, zoning approvals, and local permits, contact your municipal clerk's office or county clerk directly. Requirements vary by jurisdiction; no statewide portal covers all local requirements.