--- title: "LLC Attorney" description: "How to form a Series LLC in Illinois in 2026. Statute, filing requirements, EIN rules, liability separation, and ongoing compliance." canonical: https://llcattorney.com/states/il/series-llc-illinois image: https://llcattorney.com/images/share-cover.png source_path: /states/il/series-llc-illinois --- ## What Is a Illinois Series LLC? A Series LLC is a special type of limited liability company that allows a single "master" LLC to contain multiple separate "series" — each with its own assets, liabilities, members, and purpose. Illinois authorizes Series LLCs under Illinois Limited Liability Company Act (805 ILCS 180/37-40). Each series in a Illinois Series LLC has its own liability protection — debts and obligations of one series cannot reach the assets of another series, as long as proper records and accounts are maintained separately. **Important:** A Series LLC is more complex than a standard LLC. Each series requires its own operating agreement provisions, separate bookkeeping, and potentially a separate EIN. LLC Attorney recommends consulting with an attorney before forming a Series LLC to confirm it matches your actual use case. ## Who Uses a Illinois Series LLC? Series LLCs are most common among: - **Real estate investors** — holding multiple properties in separate series so that a liability from one property cannot reach the others - **Fund managers and investment vehicles** — organizing multiple investment pools under one legal umbrella - **Franchise-style businesses** — operating multiple locations as separate series under a single master entity - **Business owners with multiple ventures** — maintaining separate businesses under one filing structure to reduce annual fees ## How to Form a Series LLC in Illinois 1 ### Form the Master LLC File Articles of Organization with the Illinois Secretary of State. The formation documents must explicitly designate the entity as a Series LLC and state that individual series may have separate liability. Formation fee: $500 master LLC formation fee; $50 per series designation. 2 ### Draft a Comprehensive Operating Agreement The master operating agreement must establish the framework for creating and governing individual series — including membership allocations, voting rights, and the liability separation mechanics. Each series may also have its own series operating agreement. 3 ### Create Individual Series Each series is designated internally through your operating agreement — you do not typically file separate formation documents with the state for each series. Document the creation, purpose, assets, and members of each series in writing. 4 ### Obtain a Separate EIN for Each Series The IRS treats each series as a separate entity for tax purposes. Each series that has its own assets, members, or income should obtain its own Employer Identification Number (EIN) from the IRS. 5 ### Maintain Separate Records and Accounts To preserve the liability separation between series, each series must maintain separate accounting records and, ideally, separate bank accounts. Commingling funds between series can undermine the liability shield. ## Ongoing Requirements for Illinois Series LLCs - **Annual report** — the master LLC must file its annual report with the Illinois Secretary of State; individual series are covered under the same filing - **Separate books** — each series must maintain its own financial records to preserve liability separation - **Separate bank accounts** — best practice is one dedicated account per series - **Separate EINs** — each series generally needs its own EIN from the IRS for tax filing purposes - **Registered agent** — the master LLC must maintain a registered agent in Illinois with a physical address ## Form Your Illinois Series LLC LLC Attorney handles Series LLC formation in Illinois — including the master LLC filing, operating agreement drafting for each series, and registered agent service. Ready to Launch Your Business in il?Follow our fast, easy process to get started right now.[Start My Business](https://app.llcattorney.com/formation?intake_type=formation) ## Illinois Series LLC — FAQs ### What is a Series LLC in Illinois? ![icon](/_next/image?url=%2Fimages%2Ficons%2FfaqPlus.png&w=128&q=75) A Illinois Series LLC is a master LLC that contains multiple legally separate series, each with its own assets, liabilities, and members. Authorized under Illinois Limited Liability Company Act (805 ILCS 180/37-40), it allows multiple business ventures or assets to be held under one filing while maintaining liability separation between them. ### How is a Illinois Series LLC taxed? ![icon](/_next/image?url=%2Fimages%2Ficons%2FfaqPlus.png&w=128&q=75) The IRS has not issued final guidance on how Series LLCs are taxed. In practice, each series that has its own assets and members is generally treated as a separate entity for tax purposes and requires its own EIN. Consult a CPA or tax attorney familiar with Series LLC taxation before forming one. ### Does each series in a Illinois Series LLC need its own EIN? ![icon](/_next/image?url=%2Fimages%2Ficons%2FfaqPlus.png&w=128&q=75) Yes — the IRS generally treats each series as a separate entity, and each series with its own membership, assets, or income needs its own EIN. ### Is a Illinois Series LLC right for real estate investors? ![icon](/_next/image?url=%2Fimages%2Ficons%2FfaqPlus.png&w=128&q=75) Series LLCs are popular with real estate investors who want to hold multiple properties in separate liability buckets without paying separate state filing fees for each property. Illinois's statute provides liability separation between series, but maintaining it requires strict separation of records and bank accounts per series. ### How is a Illinois Series LLC different from forming multiple LLCs? ![icon](/_next/image?url=%2Fimages%2Ficons%2FfaqPlus.png&w=128&q=75) A Series LLC uses a single master LLC filing for multiple asset buckets, which may reduce state filing and annual report fees. Multiple standard LLCs each have their own filing, with clearer legal certainty about liability separation. The Series LLC approach saves on fees but adds complexity; multiple LLCs are simpler but cost more. An attorney can help you evaluate which structure is right for your situation. ### Does LLC Attorney form Series LLCs in Illinois? ![icon](/_next/image?url=%2Fimages%2Ficons%2FfaqPlus.png&w=128&q=75) Yes. LLC Attorney handles Illinois Series LLC formation — including the master LLC filing with the Illinois Secretary of State, operating agreement drafting for the master LLC and individual series, and registered agent service. ## Related Illinois LLC Resources - [Illinois LLC Formation Guide](/states/il) - [Illinois Registered Agent Service](/states/il/registered-agent-illinois) - [How to Amend Your Illinois LLC](/states/il/llc-amendment-illinois)