llc formationUpdated 2026-03-31
How to Start an LLC in Illinois
## Introduction
Illinois offers a straightforward path to LLC formation under the Illinois Limited Liability Company Act (805 ILCS 180/). You'll file Articles of Organization with the Secretary of State for a flat $150 fee, with standard processing in about 10 business days. Illinois supports single-member and multi-member LLCs, series LLCs, and professional LLCs through the Department of Financial and Professional Regulation. The state imposes no general business license requirement, though you'll need sales tax registration if you make taxable sales and professional licensure if your LLC renders regulated services.
**What You'll Accomplish in This Guide:**
- Select a compliant LLC name and reserve it (optional)
- Appoint a registered agent and office in Illinois
- File your Articles of Organization online ($150)
- Obtain an EIN from the IRS (free)
- Register for Illinois sales tax and business taxes
- Obtain professional licenses or local permits as required
- Create an operating agreement to govern your LLC
The entire process typically takes 2–4 weeks from name selection to full operational readiness.
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## Step 1: Choose and Reserve Your LLC Name
Your LLC name must include "Limited Liability Company," "LLC," or "L.L.C." and be distinguishable from all existing Illinois business entities on file with the Secretary of State. You can search available names free at https://apps.ilsos.gov/businessentitysearch/ and reserve a name for 90 days by paying a $25 fee.
### Illinois LLC Naming Requirements
Under 805 ILCS 180/1-10, your LLC name must contain one of three designators: **Limited Liability Company**, **LLC**, or **L.L.C.** Your name must be distinguishable from all domestic and foreign LLCs, corporations, assumed names, and reserved or registered names already on file with the Secretary of State.
You cannot use certain restricted words in your LLC name. Prohibited terms include Corporation, Corp., Incorporated, Inc., Ltd., Co., Limited Partnership, and LP. Additionally, words indicating insurance, assurance, banking, or corporate-fiduciary authority are restricted under 805 ILCS 180/1-10, 205 ILCS 620/1-9, and 205 ILCS 5/46. If your business involves trust, trustee, fiduciary, bank, banker, or banking services, you must obtain separate approval before using those terms.
### Search for Name Availability
Start by searching the Illinois Secretary of State's business entity database at https://apps.ilsos.gov/businessentitysearch/. This free search tool lets you verify that your desired name is available and distinguishable from existing entities. Search results are updated regularly, so you can confirm availability before proceeding.
The search takes seconds and returns results showing whether your name is available, reserved, or already in use by another entity. If your first choice is unavailable, the search results suggest similar available names.
### Reserve Your Name (Optional)
Once you've identified an available name, you can reserve it for 90 days by filing a name reservation request with the Secretary of State. The reservation fee is $25. A reserved name gives you time to prepare your Articles of Organization without risk that someone else will register the same name. You can file your Articles of Organization at any point during the 90-day reservation period.
You can reserve a name online at https://apps.ilsos.gov/llcarticles/index.jsp or by mail to the Secretary of State. Online reservation is faster and recommended.
### Plan for an Assumed Name (DBA)
If you plan to operate your LLC under a name different from the one in your Articles of Organization, you'll need to file an assumed name (DBA) with the Illinois Secretary of State. The assumed name filing fee is $120 for 2026 (the fee varies by year). Unlike some states, Illinois LLCs file assumed names with the Secretary of State rather than at the county level.
Your assumed name remains effective until the first day of your LLC's anniversary month in the next calendar year evenly divisible by five, then renews automatically for five-year periods. If you use a DBA, customers and vendors will see that name on invoices and signage, but your official LLC name (the one in your Articles of Organization) remains your legal entity name.
| Naming Task | Cost | Timeline |
|---|---|---|
| Business entity search | Free | Instant |
| Name reservation | $25 | 90 days |
| Assumed name (DBA) filing | $120 | ~10 days |
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## Step 2: Appoint a Registered Agent and Registered Office
Every Illinois LLC must appoint and maintain a registered agent and registered office located in Illinois before filing your Articles of Organization. Your registered agent receives legal documents on behalf of your LLC, and the registered office is the physical street address where your agent conducts business.
### Who Can Serve as Your Registered Agent
Under 805 ILCS 180/1-35 and 805 ILCS 180/1-50, your registered agent must be either an individual who resides in Illinois or a business entity authorized to transact business in Illinois. You cannot use the Illinois Secretary of State as your registered agent. If you choose an individual, that person must live in Illinois; if you choose a business entity (such as a professional registered agent service), it must be licensed or authorized to operate in Illinois.
Your registered agent can be a member, manager, organizer, or employee of your LLC. You should only name someone as registered agent after they have agreed to serve in that role.
### Registered Office Requirements
Your registered office must have a physical street address or rural route plus box number located in Illinois—you cannot use a P.O. Box alone. The registered office address must match the business office address of your registered agent. This requirement ensures that legal documents can be physically delivered to your LLC during business hours.
If your registered agent is an individual, their home address can serve as the registered office if they conduct business there. If your registered agent is a business entity, the registered office must be the business office address where the entity conducts operations.
### Changing Your Registered Agent Later
If you need to change your registered agent or registered office after formation, you'll file a Statement of Change of Registered Agent and/or Registered Office with the Illinois Secretary of State for a $25 fee. This change takes effect upon filing and does not require consent from the new agent.
| Registered Agent Option | Cost | Best For |
|---|---|---|
| Self (if Illinois resident) | $0 | Solo founders, local operations |
| Employee or manager | $0 | Established teams |
| Professional agent service | $100–$300/year | Out-of-state owners, privacy |
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## Step 3: File Your Articles of Organization
Your Articles of Organization is the formation document you file with the Illinois Secretary of State to create your LLC. This document is governed by 805 ILCS 180/5-5 and 805 ILCS 180/5-40. Filing costs $150 for standard processing (about 10 business days) or $250 total ($150 + $100 expedited fee) for 24-hour service.
### Gather Required Information
Your Articles of Organization must include:
- **LLC name** with an approved designator (LLC, Limited Liability Company, or L.L.C.)
- **Principal place of business address** in Illinois
- **Registered agent name** and **Illinois registered office address**
- **LLC purpose** (you may use "any lawful purpose")
- **Duration** (if not perpetual, specify the end date)
- **Names and business addresses** of initial managers or members with manager authority
- **Organizer names, addresses, and signatures** (one or more organizers required)
- **Effective date** (optional; if you want the LLC to form on a date later than filing, but no more than 60 days after filing)
You can form an Illinois LLC with one or more organizers. An organizer may be an individual age 18 or older or another business entity. Foreign owners are permitted.
### File Online
The Secretary of State's online filing system is at https://apps.ilsos.gov/llcarticles/index.jsp. Online filing is the fastest and most convenient method. You'll upload your Articles, pay the $150 fee by credit card, and receive confirmation immediately. Standard review takes about 10 business days.
The online system guides you through each required field and validates your information before submission. You can save your progress and return later if needed. Once submitted, you'll receive a confirmation email with your file number.
### File by Mail (Alternative)
You may also mail your Articles of Organization to:
**Illinois Secretary of State**
Department of Business Services, Limited Liability Division
501 S. Second St., Rm. 350
Springfield, IL 62756
Or:
**Illinois Secretary of State**
69 W. Washington St., Ste. 1240
Chicago, IL 60602
Include a check for $150 payable to the Illinois Secretary of State. Mail filing takes longer than online filing—typically 2–3 weeks.
### Confirm Your Formation
Once the Secretary of State approves your Articles, you'll receive a Certificate of Organization. This document proves your LLC exists and is in good standing. Keep it in your business records. You'll need to present this certificate when opening a business bank account and when registering for licenses and permits.
| Filing Method | Fee | Processing Time |
|---|---|---|
| Online | $150 | ~10 business days |
| Online (expedited) | $250 | 24 hours |
| Mail | $150 | 2–3 weeks |
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## Step 4: Draft an Operating Agreement
An operating agreement is a contract among your LLC's members and managers that governs how the business operates. Illinois law does not require a written operating agreement (805 ILCS 180/15-5), but the statute provides default rules only if your agreement is silent. For multi-member LLCs and single-member LLCs with outside investors, a written agreement is essential.
### Understand Default Rules
If you do not have an operating agreement, Illinois law provides that your LLC is member-managed (not manager-managed) and that members share profits and losses equally. The operating agreement may modify most of these default rules, subject to statutory limits.
Under 805 ILCS 180/15-5, any person who becomes a member after formation is deemed to assent to the existing operating agreement. This means you should finalize your operating agreement before admitting new members or outside investors.
### Include Key Provisions
A typical operating agreement should address:
- **Member names, ownership percentages, and capital contributions** — Specify each member's ownership stake and initial investment
- **Profit and loss allocation** — Describe how profits and losses are distributed (can differ from ownership percentages)
- **Management structure** — Specify member-managed or manager-managed and name initial managers
- **Member voting rights and decision-making procedures** — Define which decisions require unanimous consent and which require majority vote
- **Distributions and withdrawal rules** — Establish when and how profits are distributed and what happens if a member wants to leave
- **Admission of new members** — Describe the process and requirements for adding new members
- **Dissolution and liquidation procedures** — Outline how the LLC closes and how assets are distributed
- **Buy-sell or buyout provisions** — Address what happens if a member dies, becomes disabled, or wants to leave
### Single-Member LLCs
Even if you are the sole member, consider a written operating agreement. It clarifies that your LLC is a separate legal entity and supports the liability shield if you are ever sued. It also simplifies future financing or sale of the business.
### Professional LLCs
If your LLC will render professional services licensed by the Illinois Department of Financial and Professional Regulation (law, accounting, medicine, etc.), your operating agreement must comply with the Professional Limited Liability Company Act (805 ILCS 185/). Consult an attorney licensed in your profession before finalizing your agreement.
### Amending Your Operating Agreement
You can amend your operating agreement at any time if all members consent. Document amendments in writing and have all members sign. Major amendments—such as changing management structure, adding or removing members, or altering profit allocation—should be approved by unanimous vote unless your operating agreement specifies a lower threshold.
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## Step 5: Obtain an EIN from the IRS
An Employer Identification Number (EIN) is a nine-digit identifier the IRS uses to track your business for tax purposes. You need an EIN if your LLC has employees, operates as a corporation or partnership for tax purposes, or maintains a business bank account in the LLC's name (which we recommend).
### Apply for an EIN Online
Visit the IRS website at https://www.irs.gov/ein and apply online. The application is free and takes about 15 minutes. You'll receive your EIN immediately upon approval. You do not need to wait for your Articles of Organization to be approved; you can apply as soon as you have decided on your LLC name and structure.
The online application guides you through required fields and validates your information before submission. You'll need your LLC name, principal business address, and the name and Social Security Number of the responsible party (typically the owner or manager).
### Provide Required Information
The IRS will ask for your LLC name, principal business address, business type (LLC), and the names and Social Security numbers of all members and managers. Have your Articles of Organization draft or your formation documents handy.
You can also apply by phone at 1-800-829-4933 or by mail using Form SS-4. Phone applications take about 15 minutes; mail applications take 4–6 weeks.
### Sole Proprietors and Single-Member LLCs
If your single-member LLC is taxed as a sole proprietorship (the default), you may use your personal Social Security number instead of an EIN. However, obtaining an EIN keeps your personal and business finances separate and is recommended.
### Keep Your EIN Safe
Once you receive your EIN, store it securely. You'll need it to open a business bank account, file tax returns, and hire employees. The IRS will send you an EIN letter by mail within 2–4 weeks if you apply by phone or mail; online applicants receive their EIN immediately.
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## Step 6: Open a Business Bank Account
Opening a dedicated business bank account separates your personal and business finances, simplifies accounting, and strengthens your liability protection. Banks require proof of your LLC's existence and your EIN.
### Gather Required Documents
Most banks will ask for:
- Your **Certificate of Organization** (issued by the Illinois Secretary of State)
- Your **EIN letter from the IRS**
- A copy of your **Articles of Organization**
- A **government-issued ID** (driver's license or passport)
- Your **operating agreement** (some banks request this; not required if you don't have one)
Your Certificate of Organization is the official filing receipt you receive after your Articles are approved by the Secretary of State—typically within 10 business days for standard online filings.
### Choose a Bank
Select a bank that offers business checking accounts with reasonable fees and online banking. Many banks offer accounts with no minimum balance or monthly fees for new businesses. Call ahead and confirm they accept Illinois LLCs and ask whether they require an operating agreement or any additional documentation.
### Open the Account
Visit your bank in person or apply online. Provide the documents listed above and sign the account agreement. You'll receive a
## Related Pages
- [Illinois Llc Cost](/states/illinois/llc-cost/)
- [Illinois Llc Taxes](/states/illinois/llc-taxes/)
- [Illinois Annual Requirements](/states/illinois/llc-annual-report/)
- [Illinois Registered Agent](/states/illinois/registered-agent/)
- [Illinois Operating Agreement](/states/illinois/llc-operating-agreement/)