You carry two fears, and they have two different tools. The lawsuit fear is real, and the series LLC answers it. A series LLC is an Illinois entity structure. It walls off liability between properties, so one judgment cannot take every building. The tax fear is usually empty. An S corp is a federal tax election. Federal law already exempts passive rent from self-employment tax, so the election saves $0 on rent. It still costs $4,000 to $8,000 per year to run. I form Illinois series LLCs for $1,050 flat, and that fee includes the $400 state filing fee.
Your CPA said the words S corp. A video said one lawsuit can take every building you own. Now you sit with two fears at once. You fear a tax bill you overpay every April. You fear a tenant judgment that swallows your whole portfolio. The two warnings cannot both be right for you, because they describe two different problems. An S corp touches only the tax problem. A series LLC touches only the lawsuit problem. This page shows you which fear is real on your facts, and what each structure costs to run. I priced the tax side line by line in my LLC vs. S-Corp guide.
What Is a Series LLC?
A series LLC is one Illinois limited liability company that can create protected "series" underneath it. Each series holds its own assets. Each series carries its own liabilities. Illinois authorized the structure under 805 ILCS 180/37-40. Illinois was one of the first states to do it. The parent LLC is the shell. Each rental property goes into its own series. A judgment against one series cannot reach the assets of the other series. That wall holds only if you maintain each series as a separate unit.
The mechanics matter more than the concept. Illinois formation has four requirements:
- File Form LLC-5.5(S), not the standard Form LLC-5.5. The Secretary of State charges a $400 filing fee for that form.
- Put the statutory language that limits liability between series, from 805 ILCS 180/37-40(b), in the Articles.
- Create each individual series with a $50 Certificate of Designation.
- Give each series its own books and its own bank account. Name the specific series as grantee on each deed, not the parent.
Get any step wrong, and you paid for compartments a plaintiff's attorney will collapse in discovery. I cover the full structure, the banking headaches, and Illinois veil-piercing law in my dedicated series LLC guide.
Notice what is missing from that description: taxes. A series LLC changes nothing about how the IRS taxes your rent. A single-owner series LLC is a pass-through by default. The rent flows to Schedule E on your personal return. It flows the same way in a standard $750 LLC or in your own name. The series LLC is a liability tool. That is its entire job.
What Does an S Corp Election Actually Do?
You do not form an S corp at the Illinois Secretary of State. An S corp is a tax election. You file it with the IRS on Form 2553. The election changes how the IRS taxes an entity you already own. The pitch goes like this. You pay yourself a "reasonable salary." Only the salary carries the 15.3% FICA tax. Profits above the salary come out as distributions, and distributions carry no FICA. For genuinely active income, that split saves real money.
The election has a price whether or not it saves you anything. After you elect, you must do four things:
- Run payroll on yourself.
- File quarterly Form 941s.
- Prepare a separate Form 1120-S corporate return plus Illinois Form IL-1120-ST.
- Pay the employer half of FICA on your own salary.
My line-by-line cost breakdown of the S corp for landlords puts the realistic annual cost at $4,000 to $8,000. Illinois then adds its 1.5% personal property replacement tax on S corp net income. A single-member LLC never pays that tax. None of this condemns the S corp itself. For the right income, the FICA savings swallow those costs whole. The question is whether your income is the right income.
One Lawsuit, Three Buildings
Test the lawsuit fear on one concrete case. You own three rental buildings. A tenant falls on the stairs at building one. The tenant sues and wins a $400,000 judgment. My series LLC guide runs the same numbers in more depth. The judgment reaches different assets under each setup.
Setup 1: One plain LLC holds all three buildings
The LLC is one legal person. Every asset inside it stands behind the judgment. The plaintiff can reach building one, building two, and building three. The wall around your personal assets can hold. The wall between your buildings does not exist. The video warned you about this setup, and the warning is fair.
Setup 2: A series LLC, one series per building
The judgment lands on the series that holds building one. Say that building is worth $285,000. The plaintiff can take that building. The plaintiff cannot reach the series that hold buildings two and three. 805 ILCS 180/37-40 draws that wall. The wall holds only if you keep separate books and separate bank accounts. Put the correct series name on every deed and every lease.
Setup 3: Any entity with an S corp election
The election changes nothing in this lawsuit. An S corp is a tax election, not a wall. The court does not care how the IRS taxes your rent. One entity that holds all three buildings exposes all three buildings, S election or not. The structure your CPA suggested for April does no work in the courtroom.
Why Does the S Election Do Nothing for Passive Rent?
IRC Section 1402(a)(1) excludes "rentals from real estate" from net earnings from self-employment. Your rent carries no self-employment tax today. That is true in an LLC, in a series LLC, and in your own name. The whole S corp pitch is FICA savings on distributions. The FICA on passive rent is already zero. No election can cut a tax below nothing. The IRS taxes rental income and flip income differently. I explain that split in my guide to real estate earnings and taxes.
The election is not merely useless for a landlord. It can do damage:
- S corp shareholders cannot count the building's mortgage toward tax basis the way LLC members can under IRC Section 752. That limit can freeze depreciation losses exactly when a leveraged rental produces them.
- A 1031 exchange must happen at the entity level, not personally.
- A transfer of a leveraged, long-depreciated building into the S structure can trigger immediate gain. IRC Section 357(c) applies when the debt exceeds your basis.
- The exit is worse than the entrance. Appreciated buildings tend to get stuck. IRC Section 311(b) treats a distribution of appreciated property as a sale at fair market value. The shareholders recognize the gain with no cash in hand to pay the tax.
What Does Each One Cost Per Year?
Put a price tag on each fear. Start with the tax side. Assume $75,000 of net passive rent. My LLC vs. S-Corp guide prices this same example line by line. The S election saves no tax on that rent. The election still sends you these bills every year:
| Line Item | Amount | Notes |
|---|---|---|
| Self-employment tax saved on rent | $0 | Rent is exempt under IRC Section 1402(a)(1) |
| Form 1120-S plus IL-1120-ST prep | $1,200 to $2,500 | A full corporate return, every year |
| Payroll service | $600 to $1,200 | Quarterly Form 941s and W-2s |
| Employer FICA on a $30,000 salary | $2,295 | You pay the employer half yourself |
| Extra bookkeeping | $500 to $1,500 | Basis tracking and payroll records |
| Cost to run the election | $4,000 to $8,000 | Per year, to save $0 on rent |
Illinois then adds its 1.5% personal property replacement tax on the S corp's net income. On these numbers, that tax is about $675 more. A single-member LLC never pays it.
Now price the lawsuit side. The series LLC costs $1,050 once, and the $400 state filing fee sits inside that number. Each series costs one $50 Certificate of Designation. After that, the state bills are small. The parent LLC files a $75 annual report. Each active series files a $50 annual report. Three buildings cost $225 per year to keep protected.
"Twice a month someone asks me for an S corp. What they usually need is a wall between their buildings."
Series LLC: $1,050 Flat Fee. State Filing Fee Included.
Bring your property list to a free 30-minute call. I will tell you which structure fits: a series LLC, a standard LLC, or a separate S-taxed entity. You get exact flat-fee pricing before we hang up.
All consultations are confidential.
When Does the S Corp Genuinely Win?
The S corp wins whenever the income is active. Flip profit is dealer income. It is fully exposed to self-employment tax. A flipper with real volume can save five figures a year with the election. I concede that case in the LLC vs. S-Corp guide, and I concede it here too. Wholesale assignment fees are the same story. They are active income, and the salary-plus-distribution split works on them. A property management arm works the same way. It can charge management fees to outside owners, or it can pay you for running your own portfolio. Those fees are earned compensation, not rent. The election can shelter part of them from FICA.
My planning heuristic: the S corp math usually starts working near $80,000 of active income. The FICA savings must outrun the $4,000 to $8,000 in annual costs before you keep a dollar. The heuristic is a rule of thumb, not a law of nature. It still screens out most landlords instantly. Some investors buy through subject-to purchases, wraps, and seller financing. Those investors plan the entity layer and the tax layer together. I do that work on the creative financing side of my practice.
Can You Have Both at Once?
Technically, yes. A series LLC is still an LLC, and an LLC can file Form 2553. I almost never recommend the combination for a rental portfolio. I have two reasons. First, the election drags every S corp problem above into a structure built to hold appreciating buildings long term. Second, the federal tax treatment of individual series is genuinely unsettled. The IRS proposed regulations in 2010 that would treat each series as a separate entity for federal tax purposes. The IRS never finalized those regulations. Illinois already treats each series as a separate entity for state tax purposes. An S election on top of that stack buys you a very expensive CPA relationship.
The version of "both" that works is two entities with two different jobs. The series LLC holds the rentals. It stays on default pass-through taxation, so the rent lands on Schedule E untouched. A separate standalone LLC runs the active business: the flips, the wholesaling, or the management arm. That entity takes the S election once its income justifies the annual costs. Neither structure contaminates the other. You can shut down or restructure the active entity without touching the buildings. Designing that split is a 30-minute conversation with my office, not a weekend of forum research. That judgment call separates an attorney-built structure from a template. I walk through the difference in DIY LLC vs. hiring an attorney.
How Do the Two Compare Side by Side?
| Question | Series LLC | S Corp Election |
|---|---|---|
| What it is | Illinois entity structure | Federal tax election |
| Cost to start | $1,050 flat | $0 to elect |
| Cost each year | $75 + $50 per series | $4,000 to $8,000 |
| Walls between buildings | ✓ One wall each | ✗ No wall at all |
| Tax saved on rent | ✓ Already $0 owed | ✗ Saves $0 more |
| Payroll duties | ✓ None | ✗ Salary and filings |
| 1031 exchanges | ✓ Clean, single owner | ✗ Entity level only |
| Flips and wholesaling | ✗ Wrong tool | ✓ Real FICA savings |
| One Illinois rental | ✗ The $750 LLC wins | ✗ Does nothing |
| Property in other states | ✗ Separate LLCs win | ✗ Wrong problem |
Read the last three rows again before you buy anything. The series LLC loses to a plain LLC on a one-property portfolio. It loses to separate LLCs the moment you own outside Illinois, because other states may not honor Illinois series walls. The S corp beats everything on genuinely active income. A structure earns its fee only when it matches your facts. That is why the consultation is free, and why my recommendation is sometimes "keep it simple."
What Should You Ask Your CPA?
Do not argue with your CPA from a forum thread. Bring three questions to the next meeting instead. The answers will sort your situation in thirty minutes.
Ask: "Show me the self-employment tax on my rent."
Look at the number, not the pitch. IRC Section 1402(a)(1) already sets that number at $0 for passive rent. A tax of $0 leaves the S election nothing to save.
Ask: "What will the election cost me to run each year?"
Add the 1120-S prep, the payroll service, and the bookkeeping. Write the total down. Compare that total to the tax the election saves. For passive rent, the saving is $0.
Ask: "Which part of my income is active?"
Flip profit, wholesale fees, and management fees are active. Rent is not. If the active part clears about $80,000 per year, price an S election on a separate entity. Then call me about the walls between your buildings.
Frequently Asked Questions
Further Reading
$1,050. One Filing. A Wall Around Every Building.
The fee includes the series Articles of Organization, the master operating agreement, the EIN, and the $400 state fee. Your rent stays on Schedule E. No payroll company ever sends you an invoice.