Last Updated: June 6, 2024, 12:33 pm by TRUiC Team

How To Start a Series LLC in Illinois

A series LLC in Illinois is a special type of LLC that provides specific liability and tax benefits to its owners and members. The series LLC consists of a master LLC and one or more individual series that branch off from it.

If you want to learn more about the basics of series LLCs, check out our What Is a Series LLC page.

Starting your own series LLC in Illinois doesn’t have to be difficult. Our step-by-step guide makes it simple!

  1. Name Your Series LLC
  2. Choose a Registered Agent
  3. File the Articles of Organization
  4. File the Certificate of Designation
  5. Create a Series LLC Operating Agreement
  6. Obtain an EIN

Step 1: Name Your Illinois Series LLC

Before naming your series LLC, you should know the answers to these questions:

  • What are the laws for naming an Illinois series LLC?
  • What are some general tips for naming a series LLC?
  • Is my business name available in Illinois?
  • Is my business name available as a URL and if so, how do I buy it?

1. Series LLC naming rules vary from state to state. In Illinois, you are required to follow traditional LLC naming laws and you must include the full name of the parent LLC in the name of each child series.

Follow the required Illinois LLC Naming Rules:

  • Your name must include the phrase “limited liability company,” or one of its abbreviations (LLC or L.L.C.).
  • Your name cannot include words that could confuse your LLC with a government agency.
  • Restricted words (e.g. Bank, Attorney, University) may require additional paperwork and a licensed individual, such as a doctor or lawyer, to be part of your LLC.
  • The name of the child series must contain the name of the parent series.

2. Consider these general tips for making your series’ names more recognizable, uniform, and clear:

  • Use the word “protected series” within the name of each company.
  • Name the parent LLC in a way that distinguishes it from the child series.
  • Include the full name of the parent LLC in the name of each child series.
  • The name of the child series should include the name of the assets it holds. This creates a clearer asset picture to the public and creditors.
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Example of a series LLC naming system that uses both the state of Illinois requirements and general tips:

My Holdings Co., LLC, a series LLC

123 Main Street, LLC, an individual protected series of My Holdings Co., LLC, a series LLC

123 Division Street, LLC, an individual protected series of My Holdings Co., LLC, a series LLC

3. Is my business name available in Illinois? Make sure the name you want isn't already taken by doing a name search on the Illinois Secretary of State "Cyberdrive Illinois" website.

4. Is my business name available as a URL? We recommend that you check to see if your business name is available as a web domain. Even if you don't plan to make a business website today, you may want to buy the URL in order to prevent others from acquiring it.


Use a DBA, also called an assumed name in Illinois, for the child series if the name is too long for good business branding.

Find a Domain Now

Not sure what to name your business? Check out our LLC Name Generator.

Step 2: Choose an Illinois Series LLC Registered Agent

You are required to nominate a Registered Agent for your Illinois series LLC. The Registered Agent for the parent LLC will need to be the same for each child series.

What is a Registered Agent? A registered agent is a person or business that agrees to send and receive legal papers on behalf of your series LLC. Such papers include service of process of legal action (if you are sued) and state filings.

Who can be a Registered Agent? A registered agent must be a resident of Illinois or a corporation authorized to transact business in Illinois. You may elect an individual within the company including yourself.

Learn more about the role of a registered agent and why you should consider hiring a professional service.

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Recommended: Northwest provides registered agent services for series LLCs. A subscription will need to be purchased for each LLC in the series ($125/year/LLC).

Step 3: File The Articles of Organization

To register your series LLC, you will need to file the Articles of Organization with the State of Illinois. This can be done online or by mail.

Illinois has a specific Articles of Organization form for the series LLC.

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We recommend consulting with an attorney when completing your series LLC Articles of Organization.

Or read our free guide to form a standard single or multi-member LLC in Illinois.

After filing the Articles of Organization, you must submit your Certificate of Designation for each child series.

To add one or more child series later on, you must complete the Articles of Amendment. Remember to also file another Certificate of Designation (see below).

Step 4: File the Certificate of Designation for a Series LLC

You must complete a Certificate of Designation for each child series but only AFTER you file your Articles of Organization.

Step 5: Create a Series LLC Operating Agreement

An operating agreement is required when starting a series LLC in Illinois. The operating agreement does not have to be filed with the state.

What is an operating agreement? An operating agreement is a legal document outlining the ownership and operating procedures of an LLC.

Why are operating agreements important? For a series LLC in Illinois, the operating agreement is important because it provides for the establishment of the series and it outlines the operations and structure of the series.

We recommend having an Attorney assist you in preparing your Illinois series LLC operating agreement.

Step 6: Obtain an EIN

What is an EIN? The Employer Identification Number (EIN), or Federal Tax Identification Number, is used to identify a business entity. Each of the child series in your series LLC will require an EIN.

Why do I need an EIN? An EIN is required for the following:

  • To open a business bank account for the company
  • For Federal and State tax purposes
  • To hire employees for the company

How do I create an EIN for my series LLC? The IRS doesn’t have specific guidelines for creating an EIN for the child series of a series LLC. Experts suggest using the name of your series LLC combined with the child series name for each additional EIN.

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Example Series LLC EIN

Series LLC Name: My Holdings Co., LLC, a series LLC

EIN entry: My Holdings Co LLC a series LLC

Child Series Name: 123 Main St., LLC, an individual protected series of My Holdings Co., LLC, a series

EIN Entry: 123 Main St LLC an individual protected series of My Holdings Co LLC a series

Get an EIN

Option 1: Request an EIN from the IRS

Apply Online

- OR -

Option 2: Apply for an EIN by Mail or Fax

Download Form

Mail to:
Internal Revenue Service
Attn: EIN Operation
Cincinnati, OH 45999

Fax: (855) 641-6935

Fee: Free

Where do I get an EIN? An EIN is obtained from the IRS (free of charge) by the business owner after forming the company. This can be done online or by mail.

FOR INTERNATIONAL APPLICANTS: You do not need an SSN to obtain an EIN. Read more about applying for an EIN as an International here.

Key Steps After Forming a Series LLC

Open a Business Banking Account

A dedicated business banking account is required for each child series of a series LLC. Without dedicated accounts, the child series are NOT protected from liabilities incurred by the other child series or the parent LLC.

Set Up Accounting

Accounting and record keeping for the series LLC MUST be clear, concise, and separate. Without careful record keeping, your series might not be protected. Separate record keeping helps ensure the courts will never allow a creditor or plaintiff to pierce the corporate veil.

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Recommended: Use an accounting service to help with managing your Illinois series LLC.


Expenses are sometimes shared across the series. For example, the series might share office space. Shared costs like rent can be spread out between the child series but it must be done in a logical way that will be defensible in court.

Register Your Series for Illinois State Tax

We recommend consulting a tax professional for help in tax planning and filing for your series LLC.

Maintain your LLC: Avoid fines and the risk of dissolution.

File Your LLC Annual Report

Illinois requires LLCs to file an annual report with the Illinois Secretary of State. This can be done online, by mail, or in-person. The annual report will be filed by the parent LLC on behalf of all of the entities in your series LLC.

File Your Annual Report

OPTION 1: File Online with the State of Illinois 


- OR -

OPTION 2: File by Mail or In-Person


Fee: $150 Online, $75 By Mail (Nonrefundable)

Mail to:
Department of Business Services
Limited Liability Division
501 S. Second St., Rm. 351
Springfield, IL 62756

Due Date: Due each year prior to the first day of the month in which the LLC was formed. Reports can be filed starting 60 days prior to the due date.

Late Filings: Illinois charges a late fee of $75 by mail and $125 online. In addition, LLCs will be dissolved after 180 days for failure to file an annual report.


Report LLC Income

Reporting income for your series LLC is best handled by an accountant who is familiar with series LLC tax code.

Avoid Dissolution

Series LLCs may face fines and even automatic dissolution when they miss one or more state filings. When this happens, series LLC owners risk loss of limited liability protection. A quality registered agent service can help prevent this outcome by notifying you of upcoming filing deadlines, and even submitting reports on your behalf for an additional fee.

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Recommended: Northwest offers a reliable registered agent service and excellent customer support.

Become a knowledgeable LLC owner. Learn more about these important topics.

Obtain a Certificate of Good Standing

A Certificate of Good Standing verifies that your series LLC was legally formed and has been properly maintained. Several instances where you might need to get one include:

  • Seeking funding from banks or other lenders
  • Forming your business as a foreign LLC in another state
  • Obtaining or renewing specific business licenses or permits


You can order a Illinois Certificate of Good Standing online.

Request Certificate of Good Standing Online


Fee: $25 (Nonrefundable)

Dissolve Your Illinois LLC

If at any point you no longer wish to conduct business with your series LLC, it is important to officially dissolve it. Failure to do so in a timely fashion can result in tax liabilities and penalties, or even legal trouble. To dissolve your series LLC, there are two broad steps:

  • Close your business tax accounts
  • File the Articles of Dissolution


Closing a child series will not dissolve the parent LLC. Dissolving the parent LLC will dissolve all of the child series under it.

Illinois Business Resources