Series LLCs

How a series LLC works

A series LLC is a parent LLC that can create an unlimited number of internal series, each functioning as a semi-separate business entity. Each series has its own members (which can be the same as or different from the parent), its own assets, its own liabilities, its own bank accounts, and its own operations. The key feature is liability isolation: a creditor of Series A cannot reach the assets of Series B or of the parent, provided the LLC follows state-specific formalities.

The structure was invented in Delaware in 1996, primarily for mutual fund families (each fund being a series of a single investment company LLC). It spread over the following two decades to roughly 20 other states, mostly adopted through the Uniform Limited Liability Company Act. Non-adopting states often recognize foreign series LLCs but may not honor the internal liability separation.

Real use cases where series LLCs make sense

Where you cannot form a series LLC

The 30 states without a series LLC statute don't allow you to form one under their law. You can form a series LLC in a series-LLC state (like Delaware or Texas) and register it as a foreign LLC in a non-series state, but the liability isolation between series may or may not be honored by that state's courts. For critical asset protection, forming regular separate LLCs in your operating state is usually the safer path.

Series LLC states and statutes

Taxes: the unresolved problem

The IRS proposed regulations in 2010 (REG-119921-09) treating each series as a separate entity for federal tax purposes. They were never finalized. Without final regulations, series LLC owners have three practical approaches:

1. Treat the parent LLC as the only taxpaying entity

   Each series is a disregarded division. One federal return for the whole thing. Works when all series have identical ownership.

2. File each series as its own entity

   Each series gets its own EIN and files its own Form 1065, 1120, or Schedule C. Works when series have different ownership or meaningfully different activities. More paperwork, more CPA time.

3. Hybrid approach

   Parent files one return for disregarded series with identical ownership. Series with different members file separately. Common for real estate investors who add outside co-investors to specific properties.

State tax treatment is even more variable. Illinois taxes each series as a separate entity. Delaware taxes only the parent. Texas has a unique separate registration for each series. Always involve a CPA with series LLC experience before choosing this structure. The tax complexity is real and not just theoretical.

The interstate problem

A series LLC formed in Delaware that owns rental properties in Florida is operating across a series-state and a non-series-state. Florida has not enacted a series LLC statute and Florida courts have not definitively ruled on whether a Florida-property-holding series is legally separate from its sibling series for purposes of Florida creditor claims. The answer could come out either way in a specific case.

Practical guidance: if your asset protection strategy depends on series isolation, keep all the assets in the state where you formed the series LLC. For assets located in non-series states, consider forming separate regular LLCs in each state instead. The extra formation and annual fees are often worth the certainty. The cost pillar has the state-by-state breakdown of what separate LLCs actually cost.

When a series LLC is overkill

• Single operating business. A consulting firm, an e-commerce store, a service business with one or two revenue streams doesn't need series isolation. A regular LLC is simpler and carries no tax or interstate uncertainty.
• Two properties. The administrative overhead usually doesn't pay off until you have 3+ properties. For 2 rentals, form 2 separate LLCs; the annual report fees are usually less than a CPA's extra time on series tax questions.
• Multi-state operations where some states don't recognize series. The interstate uncertainty outweighs the cost savings. Form separate LLCs in each operating state.
• Raising outside investment. Investors prefer familiar regular LLCs. Series structures add complexity that most VCs and private investors don't want to underwrite. For investment-track businesses, stick to a regular LLC and consider an eventual C-corp conversion.

Frequently Asked Questions

• What is a series LLC?

  A series LLC is a parent LLC that can create an unlimited number of sub-entities (called "series" or "protected cells") under one umbrella. Each series operates like its own separate LLC: it can own its own property, enter its own contracts, and be sued separately. The liability of each series is isolated from the others, meaning a lawsuit against Series A cannot reach the assets of Series B or the parent LLC, as long as state-specific formalities are observed.

• Which US states allow series LLCs?

  21 states have a series LLC statute: Alabama, Arkansas, Delaware, District of Columbia, Illinois, Indiana, Iowa, Kansas, Missouri, Montana, Nebraska, Nevada, North Dakota, Oklahoma, South Dakota, Tennessee, Texas, Utah, Virginia, Wisconsin, Wyoming. Delaware was first in 1996; most other states adopted the structure between 2006 and 2023. The remaining 30 states do not currently have a series LLC statute, and their courts have not definitively ruled on whether foreign series LLCs formed elsewhere can operate there with the same liability protection.

• What's the difference between a series LLC and just forming multiple separate LLCs?

  Three practical differences. First, cost: you file one set of Articles for the parent LLC and pay one formation fee; adding a new series is free or very cheap in most states. Separate LLCs require separate filings and separate annual report fees. Second, administration: a series LLC has one EIN, one operating agreement, and one tax return (in most scenarios); separate LLCs each need their own. Third, flexibility: adding or retiring a series is faster than forming or dissolving a full LLC. The tradeoff is uncertainty; series LLCs don't have the decades of case law that regular LLCs do.

• How are series LLCs taxed?

  The IRS has not issued final regulations on series LLC taxation despite decades of requests. Proposed regulations (REG-119921-09 from 2010, never finalized) treat each series as a separate entity for federal tax purposes. In practice, most series LLCs either file one federal return for the parent and treat each series as a disregarded division, or (if each series has different owners) file separate returns for each series. State treatment varies widely: some states tax the parent only, some tax each series separately, some require a separate registration for each series. Always involve a CPA with series LLC experience before electing this structure.

• When does a series LLC make sense?

  Three fact patterns where series LLCs clearly win: real estate investors holding multiple rental properties (one series per property to isolate liability); holding companies owning multiple operating subsidiaries; and investment vehicles with distinct asset classes (each series holds different investments). The common thread: you need liability isolation between distinct pools of assets, you'd otherwise form many separate LLCs, and you value the cost and administrative savings over legal certainty.

• What are the risks of using a series LLC?

  Two main risks. First, cross-series liability if formalities fail. If you commingle funds across series, don't maintain separate books, or operate inconsistently, a court can pierce between series and treat the parent plus all series as a single entity. Second, interstate unpredictability. If your series LLC formed in Delaware owns property in Florida (which has no series LLC statute), Florida courts may or may not honor the series' separate liability. For multi-state operations, separate full LLCs in each state often ends up safer despite the extra administrative cost.

• How much does a series LLC cost compared to regular LLCs?

  The parent LLC costs the same as any regular LLC formation ($35 in Montana to $500 in Massachusetts, average ~$130; see full cost breakdown). Adding each additional series is free or nearly free in most series-LLC states (Delaware adds $110 to register a series with the state; Texas is $0 for internal series formation). A 10-property real estate portfolio as a series LLC often costs $200 to $500 total in first-year state fees, versus $2,000 to $10,000 for 10 separate LLCs.

• Can I register my series LLC in a state that doesn't allow series LLCs?

  You can operate in non-series states, but the liability protection is uncertain. Most non-series states accept foreign LLC registrations from series LLCs, but they may not recognize the series-level liability separation. For example, a Delaware series LLC doing business in California registers as a foreign LLC there, but California courts have not definitively ruled whether creditors of one series can reach another series' assets held in California. For critical liability isolation, form separate regular LLCs in the states where you actually operate.

Related

• LLC formation by stateStart a regular LLC in every US state →
• LLC for rental propertySingle-property LLC vs series LLC decision →
• Holding company LLCParent-subsidiary structures without series →
• LLC cost breakdownFiling and ongoing fees for comparison →