Decision guide
Series LLC: one company, separate compartments, and the records test
A series LLC is a single limited liability company whose governing documents create separate compartments inside it, called series. Each series can hold its own assets, run its own line of business, and carry its own obligations, and in a state whose statute allows it, the debts of one series are enforceable only against that series, not against the company as a whole or the other series. That is the promise. The conditions are the point of this guide: the separation exists only where a statute creates it, only while the records the statute names are actually kept, and only as far as the banks, insurers, counterparties, and other states involved are willing to work with it. Read this as a decision guide, not a formation recipe. The statute in the state you are considering is the authority, and a structure with this many moving parts deserves an attorney in that state before the first asset is placed.
What a series is, in plain terms
Delaware's statute describes the raw material: a limited liability company agreement may establish one or more designated series of members, managers, interests, or assets, and a series may have separate rights, powers, or duties for specified property or obligations, and its own business purpose or investment objective. One company, several internal divisions with real legal edges, at least inside the state that created them. The classic user is an owner of several rental properties who would otherwise form an LLC per property, and the classic question is whether the compartments hold when one property's problem tries to reach the others.
There are two Delaware forms, and confusing them is the first error. A protected series exists by agreement plus record keeping plus a notice in the certificate of formation, with no separate state filing for the series itself. A registered series is formed by filing a certificate of registered series with the Secretary of State, which puts the series on the public record with its own name. Both rest on the same separation rule, stated for registered series in section 18-218 of the Delaware Code: to the extent the records maintained for the series account for its assets separately from the other assets of the company and of any other series, its debts and obligations are enforceable against its assets only. The registered form adds public-record machinery: a registered series can, in its own name, contract, hold title to assets, grant liens, and sue and be sued.
The three conditions the separation stands on
First, the agreement must establish or provide for the series. A series invented in a spreadsheet is not a series. The operating agreement for the company has to create the structure and the rules for each compartment before assets are assigned to it. Second, the records must actually account for each series' assets separately. The statute accepts records that reasonably identify the assets, by specific listing, category, formula, or any method where the identity of the assets is objectively determinable. It does not accept a single blended account and a promise to sort it out later. Separate books, separate bank accounts in practice, and contracts signed in the name of the right series are what the condition looks like when it is met.
Third, the notice must be in the certificate of formation. The statute requires the certificate to state the limitation on liabilities of the series, and it treats the filed certificate as notice of that limitation to the world. Skip the notice and the firewall argument is damaged at its foundation. Notice what all three conditions have in common: none of them is a fee. The separation is a discipline the statute rewards, not a product the state sells. Owners who want the protection have to run the structure every month, not just file it once.
- The company agreement establishes each series and its rules.
- Separate records account for each series' assets, objectively determinable.
- The certificate of formation carries the notice of limited liability of series.
- For a registered series, a certificate of registered series is filed for the series itself.
- Contracts, accounts, and titles name the correct series, every time.
Series LLC vs. separate LLCs: the five-year arithmetic
The honest comparison uses checked state figures, so here it is built from the Delaware record on this site: a certificate of formation costs $110, and the annual alternative entity tax is $400 per year with no annual report. Three separate Delaware LLCs, one per property, cost $330 in formation filings on day one, then $1,200 per year in annual tax, which is $6,330 over five years. One Delaware LLC holding the same three properties in series costs $110 in formation, then $400 per year, which is $2,110 over five years on the figures in the checked record. The arithmetic difference is $4,220, and it is the entire reason the structure gets attention.
Now the three cautions that belong inside the same paragraph as the saving. First, the checked record publishes the formation fee and the annual tax for an LLC. It does not publish a separate annual amount for a registered series, and registered series filings carry their own Division fees, stated on the Division of Corporations fee schedule. Add the Division's current per-series filing fee for each registered series, and any per-series amount the fee schedule or the tax statute currently states, to the $2,110 line before you quote the saving to yourself. Second, the comparison prices state charges only. Separate accounting, separate bank accounts, and per-series insurance and tax preparation cost money under both structures, and a structure whose records are the legal test tends to cost more to run carefully, not less. Third, the $4,220 is a saving only if the separation holds when tested. A saving that depends on a firewall is worth less than the same saving that depends on nothing.
Where the structure meets friction
Banking is the first friction. A series is not, in most states' eyes, a separate legal entity with its own formation certificate in the way a new LLC is, and bank onboarding staff, title companies, and insurers meet the structure rarely. Expect to explain it, to produce the statute, and occasionally to be refused. Tax handling is the second friction: whether a series files or is treated separately for a given tax is a question for the tax authority involved, answered per tax and per state, not by the series statute. The third friction is travel. A series created under Delaware law that holds property or operates in a state with no series statute asks that state to respect an internal separation its own law never created. Courts and agencies there may, or may not, and the uncertainty is priced into every serious discussion of the structure.
There is also a structural single point of failure. The series live inside one company. If the company's own record fails, if its certificate of formation is canceled over an unpaid annual tax, every compartment is standing on a canceled record. Separate LLCs fail one at a time. A series structure fails together. That is the trade in one sentence: fewer filings and one calendar, against shared fate and a separation that has to be maintained and defended rather than simply filed.
What does not go away
A series LLC still needs a registered agent for the company, still owes the company's recurring state charges, and still needs an operating agreement, in this case a substantially more detailed one, since the agreement is the document that creates the series and their rules. Delaware's statute even plans for the end: a certificate of cancellation for the company must name each registered series whose certificate has not already been canceled, which tells you the state treats the compartments as real records with their own endings, to be wound up in order. Nothing about the structure removes licenses, insurance, property taxes, or the local rules that follow each asset. It rearranges the entity layer only.
A decision worksheet
Score your facts against these prompts before you pay anyone to form anything. If the answers lean left, the separate-LLC structure usually wins on reliability. If they lean right, the series structure earns a consultation.
- Lean separate LLCs when: the assets sit in states with no series statute, lenders or insurers already resist the structure, or the compartments need to be sold or financed entirely independently.
- Lean separate LLCs when: the owners differ between ventures, because different ownership inside series complicates the agreement and the tax picture.
- Consider series when: one owner, several similar assets, all in a series state, and the owner will genuinely keep separate books, accounts, and contracts per series.
- Consider series when: the five-year state saving, recomputed with the Division's current per-series fees added, is still large enough to pay for the extra record discipline and legal advice.
- Stop and hire counsel when: any asset is real estate in another state, any lender is involved, or any series will employ people. Those facts change the analysis more than the filing fees do.
If you proceed: the setup order
First, confirm the statute in the state where the company will be formed and, separately, in every state where a series will hold assets or operate. Second, have the operating agreement drafted for the structure, establishing the series, their rules, and the record keeping method the statute's separate-accounting condition will be tested against. Third, file the certificate of formation with the limitation notice in it, and file a certificate of registered series for each series if you are using the registered form. Fourth, before any asset moves, open the separate accounts and books, retitle assets deliberately, and sign new contracts in the correct series name. Fifth, calendar the company's recurring charges and treat them as protecting every compartment at once, because they do. An asset placed into a series before the records exist for it has received the cost of the structure without the protection of it.
Common series LLC mistakes
The first mistake is commingling: one bank account, one set of books, and series that exist only as labels. That is the exact fact pattern the statute's records condition is written to refuse. The second is forming in a series state for assets in a state that has no series law, and discovering the travel problem at the worst moment. The third is skipping the certificate notice, or forming the company before the agreement establishes the series, so the compartments were never created in the order the statute expects. The fourth is treating a series like a separate company for convenience in one place, signing a contract in the company name here, titling an asset in the series name there, until nobody can say which compartment owns what. The fifth is letting the parent record lapse. In a series structure, the annual tax reminder the agent forwards is not one company's paperwork. It is the roof over every compartment.
Checklist
- Confirm a series statute exists in the formation state and in each asset state.
- Decide protected or registered series, with counsel in that state.
- Draft the agreement to establish the series and their record rules.
- File the certificate of formation with the limitation notice included.
- File a certificate of registered series for each registered series.
- Open separate books and bank accounts before moving any asset.
- Sign contracts and hold titles in the correct series name.
- Recompute the five-year cost with current per-series Division fees added.
- Calendar the parent company's recurring charges as covering every series.
- Review the structure whenever an asset, lender, or state is added.
Next step
Use the linked tools and state records before you rely on a general rule. LLC duties turn on the state, the owners, the activity, and the tax choice.
Whichever structure you choose, the parent company's report and tax dates protect every property under it. Calendar them once, correctly, before the first deadline is close.
See your filing dates ->Common questions
Does every state allow a series LLC?
No. The series is a creature of specific state statutes, Delaware's being the best known, and many states have no series law at all. A series formed under one state's statute that holds assets in a state without one faces an open question about whether the separation will be respected there. Check both states before forming, not after buying.
Is a series a separate legal entity?
Not in the way a separately formed LLC is. A Delaware registered series has real legal capacity under the statute: it can contract, hold title, grant liens, and sue and be sued in its own name. But it exists inside one company, shares that company's formation record, and ends through that company's filings. Banks and other states may treat it differently from a standalone entity, which is why the friction section of this guide matters.
Does each series need its own EIN and bank account?
Separate bank accounts and books are, in practice, how the statute's separate-records condition is satisfied, so plan on them regardless of the tax answer. The EIN and tax filing questions are answered by the tax authority and the tax involved, not by the series statute, and they vary. Put both questions to your tax professional with your structure in hand before the first series takes income.
What happens if I keep one set of books for all series?
You have removed the condition the separation stands on. The statute conditions the liability limit on records that account for each series' assets separately. Blended records are the strongest argument a creditor has that the compartments were never real. The filing created the possibility of separation. Only the records maintain it.
Can a series own real estate?
A registered series under Delaware law can hold title to assets, including real property, in its own name. The practical questions are local: whether the recording office, title insurer, and lender in the property's state will work with the structure, and whether that state respects the internal separation. Real estate in a second state is one of the facts that moves this decision from a guide to a lawyer.
What happens to the series if the parent LLC is canceled?
They stand on the canceled record. Delaware's cancellation filing for a company with registered series must name each series whose certificate has not been canceled, which is the statute telling you the compartments end through the parent record, not around it. Keeping the parent in good standing is not housekeeping in this structure. It is load bearing.