LLC vs Sole Proprietorship vs S-Corp

What Each Structure Actually Is

Most people leaving corporate life start with a confusing question: "Do I need an LLC? Should I be an S-Corp? What even is a sole proprietorship?" The confusion is understandable — the terms get thrown around interchangeably, but they describe very different things.

A sole proprietorship is the default. The moment you start doing work and getting paid outside of an employer-employee relationship, you're a sole proprietor. There's no paperwork, no filing, no registration. You and the business are legally the same entity. Every dollar of profit flows to your personal tax return on Schedule C, and you owe self-employment tax on all of it.

An LLC (Limited Liability Company) is a legal entity you create by filing with your state. It's a separate legal person — meaning your personal assets (home, savings, car) are shielded from business debts and lawsuits, provided you maintain the separation. By default, a single-member LLC is taxed exactly like a sole proprietorship: Schedule C, self-employment tax on all profits. The LLC itself pays no federal income taxes. Many people form an LLC thinking it changes their taxes. It doesn't — unless you take an additional step.

An S-Corp is not a business entity at all. It's a tax election. You file IRS Form 2553 to tell the IRS to tax your business (whether it's an LLC or a corporation) under Subchapter S of the tax code. The S-Corp election changes how you're taxed: instead of paying self-employment tax on all profits, you split your income between a W-2 salary (subject to payroll taxes) and distributions (not subject to self-employment tax). That split is where the savings come from.

The Tax Differences That Matter Most

Tax treatment is where these three structures diverge most dramatically — and where the money is. Understanding the mechanics is essential before choosing a structure.

Self-Employment Tax: The Hidden Cost of Going Solo

When you're a sole proprietor or a single-member LLC (without S-Corp election), every dollar of net profit is subject to self-employment tax — currently 15.3% on earnings up to $176,100, then 2.9% above that for Medicare. This covers your Social Security and Medicare contributions, which previously your employer paid half of. Now you pay both halves. On $100,000 of net profit, that's roughly $14,130 in self-employment taxes before you even get to income taxes.

The self-employment tax deduction gives you back 50% of what you pay as a business deduction on your personal return, which softens the blow — but you're still paying far more than a W-2 employee in the same income bracket.

How S-Corp Taxation Changes the Equation

With an S-Corp election, the IRS requires you to pay yourself a "reasonable salary" for the work you do in the business. That salary goes on a W-2, is subject to payroll taxes (15.3% split between employer and employee portions), and is deducted from business income. Everything above your salary can be taken as a distribution — which passes through to your personal return as ordinary income, but is not subject to self-employment or payroll taxes.

The savings compound quickly. If your consulting business nets $120,000 and you pay yourself a $60,000 salary, you only owe payroll taxes on $60,000 — saving roughly $9,180 in taxes compared to taking everything as self-employment income. That savings repeats every year. Before you use the War Chest Calculator to plan your financial runway, understanding your actual take-home under each structure will significantly change your numbers.

Pass-Through Taxation: What It Means

Both LLCs and S-Corps are "pass-through" entities — the business itself pays no federal income tax. Profits and losses flow to the owner's personal tax return and are taxed at individual rates (10%–37%). This avoids the "double taxation" problem of C-Corps, where profits are taxed at the corporate level (21%) and again when distributed as dividends. For most small business owners leaving corporate jobs, pass-through entities are almost always the right choice.

The Qualified Business Income (QBI) Deduction

Under Section 199A, pass-through business owners can potentially deduct 20% of qualified business income from their taxable income. Both LLCs and S-Corps can qualify — but there are income limits and restrictions for service businesses (consulting, law, financial services). Your W-2 salary from an S-Corp doesn't qualify, but K-1 distributions typically do, which can actually make the S-Corp structure more advantageous. Consult a CPA to calculate your specific benefit.

Liability Protection Compared

This is the other major structural difference — and one that sole proprietors ignore at their peril.

Sole Proprietorship: You Are the Business

As a sole proprietor, you and your business are legally inseparable. If a client sues you for a botched project, they're suing you personally. If your business takes on debt you can't repay, creditors can come after your personal savings and assets. For service businesses with minimal risk, many sole proprietors operate this way for years without incident. But one lawsuit or business debt in the wrong situation can be financially devastating.

LLC: The Core Benefit

The whole point of forming an LLC is to create a legal wall between your personal assets and business liabilities. If your LLC gets sued or owes money, your personal home, savings accounts, and car are generally protected. The caveat: this protection requires maintaining the separation — don't commingle personal and business funds, use a separate business bank account, and act in ways consistent with the LLC being a legitimate separate entity.

Some states provide stronger LLC protections than others. Delaware, Wyoming, and Nevada are popular for their strong liability protections and business-friendly laws, though forming in your home state is usually sufficient for small service businesses.

S-Corp: Same Protection as an LLC

S-Corp tax election doesn't change the underlying entity's liability protection. An LLC with S-Corp election has the same liability shield as a regular LLC. The S-Corp election only changes taxes. A corporation with S-Corp election also provides liability protection similar to any corporation.

Formation and Ongoing Costs

Sole Proprietorship

Cost to form: $0. Ongoing compliance cost: $0, beyond whatever you pay an accountant to file your Schedule C. No state registration required (though you may need a DBA — "doing business as" — if operating under a name other than your own). Annual cost is essentially whatever your tax prep costs, often $200–$500 if you hire a CPA.

LLC

Formation costs vary significantly by state. Delaware charges $90. California charges $70 to file, plus an $800 annual minimum franchise tax. New York requires expensive publication requirements that can cost $1,000–$2,000. Most states fall in the $50–$300 range for the initial filing. On top of that, most states charge annual report fees ($25–$300/year). You'll also want a registered agent if you're not using your home address — budget $50–$150/year.

S-Corp Election

Filing Form 2553 with the IRS is free. But the ongoing compliance costs are real. You'll need to run payroll (cost: $500–$1,500/year through services like Gusto or ADP), file quarterly payroll taxes, issue yourself a W-2 at year-end, and file Form 1120-S (the S-Corp tax return) — a more complex return that most CPAs charge $800–$2,000 to prepare. All-in, budget $1,500–$3,000/year for S-Corp compliance, possibly more in high-cost-of-living areas or if your accountant's rates are high.

This is why the math only works above a certain income threshold. At $40,000 net profit, S-Corp savings might be $1,500 — barely covering the compliance costs. At $100,000, the savings are typically $4,950–$8,000+, making it well worth the administrative overhead.

Side-by-Side Comparison Table

The S-Corp Tax Savings Math

Let's run the numbers at different income levels so you can see exactly when the S-Corp election pays off. These figures assume 2025 tax rules, a self-employed person filing as single, and a "reasonable salary" set at roughly 50% of net profit (a common starting point — your CPA should help determine the right number for your industry).

The savings grow dramatically as income rises, because the spread between salary (which faces payroll taxes) and distributions (which don't) widens. At $200,000 net profit, you're saving nearly $10,000 per year — a number that continues as long as you run the business. Over 10 years, that's $70,000+ in cumulative tax savings from a one-time paperwork filing.

Common Misconceptions

Misconception #1: "An LLC saves me on taxes"

This is the most common misunderstanding. A single-member LLC is taxed identically to a sole proprietorship. You still pay 15.3% self-employment tax on all profits. The LLC provides liability protection, not tax savings. If you want tax savings, you need to elect S-Corp status separately from forming the LLC.

Misconception #2: "I should form an S-Corp immediately"

Many new entrepreneurs rush to elect S-Corp status before they even have consistent revenue. If your business nets less than $60,000, S-Corp compliance costs will likely exceed your tax savings. Start as a sole proprietor or simple LLC. Use the Business Ideas Database to find a business model that can scale, then elect S-Corp once your profits justify it.

Misconception #3: "I can set my S-Corp salary to $1 to minimize taxes"

The IRS requires "reasonable compensation" — a salary in line with what you'd pay someone else to do your job. Unreasonably low salaries are an audit red flag. If caught, the IRS can reclassify distributions as salary, assess back payroll taxes, and add penalties. Use Bureau of Labor Statistics data and industry benchmarks to set a defensible salary.

Misconception #4: "S-Corp means I have to be a corporation"

Nope. An LLC can elect S-Corp tax treatment. This is actually the most common structure — an LLC for legal purposes (flexible, fewer formalities) with S-Corp taxation (salary + distributions). You get the best of both worlds: liability protection, operational simplicity, and tax optimization.

Misconception #5: "The business structure decision is permanent"

It's not. Most businesses follow a natural progression: sole proprietorship to LLC to LLC with S-Corp election as income grows. You can switch forward as your business scales. Some states also make it easy to convert an LLC to a corporation if you later need to raise venture capital (which typically requires a C-Corp).

Who Each Structure Is Best For

Choose Sole Proprietorship If:

• You're testing a business idea and haven't yet made consistent money
• Your net profit is under $30,000–$40,000 per year
• You're doing very low-risk work (writing, tutoring, minor consulting) with minimal liability exposure
• You want zero administrative overhead while you figure out if the business works
• You're doing a low-risk side hustle alongside your day job

Choose LLC (Default Tax) If:

• You have real liability exposure — client-facing work, physical products, professional services where mistakes could cost clients money
• Net profit is $40,000–$80,000 and you're not yet sure S-Corp savings justify the paperwork
• You want the professional credibility of a registered entity
• You want the option to bring on partners or members later
• You operate in a state without punishing franchise taxes on LLCs

Choose LLC + S-Corp Election If:

• Your business consistently nets $60,000 or more per year
• You can define and defend a reasonable salary for your role
• You're comfortable with quarterly payroll filings or willing to pay a service to handle them
• The $1,500–$3,000 annual compliance cost is clearly covered by tax savings
• You're building a long-term business, not just testing an idea

Decision Framework: How to Choose

Rather than agonizing over the decision, use this simple progression framework:

Stage 1 — Just Starting ($0–$40K net profit): Default to sole proprietorship. Focus on getting clients and proving your model works. The administrative simplicity lets you move fast. If you have clients visiting your home or create real liability risk, form an LLC for protection.

Stage 2 — Gaining Traction ($40K–$80K net profit): Form an LLC if you haven't already. The liability protection is worth the modest filing fees at this stage. Run the S-Corp math with a CPA — at $60K+ net profit in most states, the election starts making financial sense.

Stage 3 — Growing Consistently ($80K+ net profit): If you're consistently netting $80,000 or more, electing S-Corp status on your LLC is almost certainly the right move. The annual savings of $5,000–$10,000+ compound significantly over time.

State-Specific Warning: California imposes an $800 annual minimum franchise tax on LLCs regardless of income, plus 1.5% S-Corp tax on net income. New York City doesn't recognize S-Corp pass-through status. If you operate in these jurisdictions, the math changes — run the numbers with a local CPA before assuming the standard framework applies.

When you're mapping your exit from corporate, use the War Chest Calculator to factor in your real post-structure take-home pay. The difference between operating as a sole prop versus an S-Corp at $120,000 in revenue is often $7,000–$10,000 per year in taxes — money that either sits in your war chest or gets paid to the IRS.