Here is a number that stops most founders cold: choosing the wrong business structure can cost you between $8,000 and $25,000 a year in taxes you never needed to pay. Not through aggressive loopholes. Not through gray-area deductions. Just through the quiet, compounding damage of picking the wrong entity on day one and never revisiting it. When you are weighing S Corp LLC or C Corp, you are not making a paperwork decision. You are making the single most expensive tax decision of your business life, and most people make it based on a Google search and a gut feeling.

Here is the turn: once you understand how each entity actually taxes your income, the right choice becomes obvious for your specific situation and income level. This guide breaks down the real math, the California-specific traps, and the exact income thresholds where switching structures saves you five figures.

Quick Answer: Which Entity Wins for Your Income Level

For most California business owners earning under $40,000 in net profit, a single-member LLC taxed as a sole proprietor keeps things simple with minimal downside. Once your net profit crosses roughly $60,000, electing S Corp status on your LLC typically saves thousands in self-employment tax. A C Corp rarely wins for small operators but becomes powerful for startups seeking outside investors or businesses retaining large profits for growth.

That is the compressed version. The real decision depends on how each structure handles the two taxes that eat your income: self-employment tax and corporate income tax. Let me walk you through each one with actual numbers, because the difference between these choices is not academic. It is cash in your pocket or cash at the IRS.

What S Corp LLC or C Corp Actually Means in Plain English

Before you can choose, you need to understand that two of these are legal structures and one is a tax election living inside a legal structure. This confuses nearly everyone, so let me clear it up.

LLC (Limited Liability Company)

An LLC is a legal entity formed at the state level. In plain English, it is a shield that separates your personal assets (your house, your savings) from your business debts and lawsuits. By default, a single-owner LLC is taxed exactly like a sole proprietorship, meaning all profit flows to your personal return and gets hit with self-employment tax. The LLC is flexible because it can elect to be taxed as an S Corp or even a C Corp later.

S Corp (S Corporation)

An S Corp is not a separate legal entity you form from scratch. It is a tax election you make with the IRS using Form 2553. You can elect S Corp status on top of an LLC or a corporation. The entire point of the S Corp election is to split your income into two buckets: a reasonable salary (subject to payroll taxes) and distributions (not subject to self-employment tax). That split is where the savings live.

C Corp (C Corporation)

A C Corp is a fully separate legal and tax entity. It files its own tax return (Form 1120) and pays its own corporate tax, currently a flat 21% federal rate. The catch is double taxation: the corporation pays tax on profits, and then shareholders pay tax again on dividends they receive. For most small business owners this is a dealbreaker, but for certain growth scenarios it is a feature, not a bug.

Key Takeaway: LLC and C Corp are legal structures. S Corp is a tax election. You can be an LLC that is taxed as an S Corp, which is actually the most common winning combination for profitable small businesses.

The Self-Employment Tax Trap That Costs LLC Owners Thousands

Here is the problem that sends profitable LLC owners scrambling to their accountants every spring. As a default LLC taxed as a sole proprietor, every dollar of net profit is subject to self-employment tax at 15.3%. That covers Social Security (12.4%) and Medicare (2.9%). This is on top of your regular income tax.

Consider Marcus, a freelance marketing consultant operating as a single-member LLC in Los Angeles. In 2025 his business nets $120,000 in profit. As a default LLC, he owes self-employment tax on roughly 92.35% of that profit, which comes to about $16,900 in self-employment tax alone, before any income tax.

Now watch what happens when Marcus elects S Corp status. He pays himself a reasonable salary of $70,000 (which incurs payroll taxes) and takes the remaining $50,000 as a distribution. That $50,000 distribution is completely exempt from the 15.3% self-employment tax. The math: 15.3% of $50,000 equals roughly $7,650 in annual savings. Over five years, that is more than $38,000 Marcus keeps instead of handing to the government.

This is exactly the situation where profitable consultants and self-employed professionals leave serious money on the table by never revisiting their entity choice. If you want to see your own numbers, run them through this self-employment tax calculator before you talk to anyone.

The Reasonable Salary Rule You Cannot Ignore

The IRS is not naive about this strategy. If you pay yourself a $10,000 salary and take $110,000 in distributions, you are inviting an audit. The IRS requires S Corp owners to pay themselves a reasonable salary for the work they perform, based on what someone else would charge to do the same job. Underpaying your salary to dodge payroll tax is one of the fastest ways to trigger IRS scrutiny.

S Corp LLC or C Corp: Side-by-Side Tax Comparison

Numbers settle arguments better than theory. Here is how the three structures stack up for a business netting $120,000 in profit.

Notice the California Franchise Tax row. This is where many online guides fail California readers. California does not simply mirror federal treatment. For a full breakdown of how the S Corp election interacts with California rules, see our complete guide to S Corp tax strategy in California.

When Does a C Corp Actually Make Sense?

Most tax guides dismiss the C Corp entirely for small business, and for the solo consultant that dismissal is correct. But there are specific scenarios where the C Corp is the smartest structure available, and skipping over them leaves founders without a critical option.

You Plan to Raise Venture Capital

If you intend to take on institutional investors, you will almost certainly need to be a C Corp (specifically a Delaware C Corp). Venture funds and most angel investors will not invest in an S Corp or LLC because of restrictions on who can own shares and how profits pass through. S Corps are limited to 100 shareholders, all of whom must be U.S. citizens or residents, and they cannot have other corporations or most trusts as owners.

You Retain Profits for Growth

A C Corp pays a flat 21% federal rate. If your business earns $400,000 and you plan to reinvest most of it rather than pull it out personally, the 21% corporate rate may beat your personal marginal rate, which can climb past 37% federally plus California state tax. Growth-stage business owners who keep money inside the company for expansion sometimes find the C Corp structure genuinely advantageous.

The Qualified Small Business Stock Advantage

Here is an edge case almost no competitor guide mentions. Under Section 1202 of the tax code, if you hold qualified small business stock (QSBS) in a C Corp for at least five years, you may exclude up to 100% of the gain from federal tax when you sell, up to $10 million or 10 times your basis. For a founder planning an eventual exit, this single provision can make the C Corp structure worth millions. This is a long-game move, but it is one of the most powerful exit planning tools in the code.

KDA Case Study: Freelance Designer Saves $9,100 With an S Corp Election

Priya ran a successful freelance web design studio in San Diego, operating as a single-member LLC. By 2024 her business was netting $135,000 a year, and she was paying her default self-employment tax on every dollar of that profit. When she came to KDA, she was staring at nearly $19,000 in self-employment tax and had no idea there was a legal way to reduce it. She assumed, like many creative professionals, that an LLC was simply the right answer forever.

We ran the full entity analysis. By electing S Corp status on her existing LLC, we set her reasonable salary at $78,000 based on market rates for senior designers in her region, then structured the remaining $57,000 as a distribution exempt from self-employment tax. The 15.3% savings on that distribution came to roughly $8,700 in the first year. We also captured an additional deduction through a properly structured retirement contribution tied to her new W-2 salary, pushing her total first-year tax savings to approximately $9,100.

Priya paid $3,000 for our entity restructure, payroll setup, and the S Corp election filing. Her first-year return on that investment was about 3x, and the savings recur every single year her profit stays at this level. Three years in, she has kept more than $27,000 that would otherwise have gone to the IRS.

Ready to see how we can help you? Explore more success stories on our case studies page to discover proven strategies that have saved our clients thousands in taxes.

Common Mistake That Triggers an Audit

The single most common and dangerous mistake S Corp owners make is paying themselves an unreasonably low salary to maximize tax-free distributions. The logic is tempting: salary gets taxed, distributions do not, so minimize salary. But the IRS watches this pattern closely.

If you are a consultant generating $150,000 in profit and you pay yourself a $25,000 salary while taking $125,000 in distributions, you have painted a target on your return. The IRS can reclassify your distributions as wages, hit you with back payroll taxes, and pile on penalties and interest. According to IRS guidance on S Corporation compensation, officers who perform services must receive reasonable compensation before any distributions.

The fix is straightforward: document your salary decision. Research what the role pays in your market, write it down, and keep that justification on file. A properly set salary is both compliant and defensible. This is where working with professionals who handle entity formation and tax elections prevents a costly mistake before it ever happens.

What Is a Reasonable Salary for an S Corp Owner?

Reasonable compensation means what you would have to pay an unrelated third party to do the same work. The IRS looks at factors including your training and experience, duties and responsibilities, time devoted to the business, and comparable salaries for similar positions in your area.

• Research comparable wages using sources like the Bureau of Labor Statistics
• Document your reasoning in writing before you set the figure
• A common guideline is a 60/40 split (salary to distribution) though this varies by industry
• Higher-skill professional services often justify higher salary percentages

Pro Tip: Do not copy another business owner’s salary ratio. Your reasonable salary is specific to your role, your industry, and your region. A graphic designer and a surgeon who both net $200,000 will have very different reasonable salaries.

How Do I Switch From an LLC to an S Corp?

If you have decided the S Corp election makes sense, here is the exact process. It is not complicated, but the deadlines matter and missing them costs you a full year of savings.

1. Confirm you have an EIN. If you do not have an Employer Identification Number, apply free at IRS.gov. It takes about five minutes online.
2. File Form 2553. This is the S Corporation election form. To be effective for the current tax year, you generally must file within two months and 15 days of the start of the tax year.
3. Set up payroll. As an S Corp owner, you are now an employee and must run formal payroll with withholding. This is non-negotiable.
4. Determine your reasonable salary. Document market research supporting your chosen figure.
5. Adjust your bookkeeping. Separate salary from distributions clearly in your records.

Getting the payroll and bookkeeping right is where many self-managed S Corps stumble. Clean records are what make the whole strategy defensible, which is why solid bookkeeping and payroll support pays for itself quickly.

What If My Business Has Losses?

If your business is currently operating at a loss or barely breaking even, an S Corp election may hurt rather than help. You would be adding payroll complexity and the cost of running formal payroll without capturing any self-employment tax savings, because there is little profit to split. In loss years or very low profit years, the simpler default LLC treatment is usually the better call. The S Corp election shines specifically when consistent profit crosses the threshold where the payroll tax savings exceed the added administrative cost.

California-Specific Considerations You Cannot Skip

California adds a layer that national guides routinely ignore, and it changes the math meaningfully. Every LLC and corporation in California owes an $800 annual minimum franchise tax. But S Corps face an additional 1.5% tax on net income (with the $800 minimum as the floor). C Corps face California’s 8.84% corporate tax rate on net income.

This means a California S Corp owner must factor in that 1.5% state-level tax when calculating whether the election still saves money. For most profitable businesses it still wins by a wide margin, because the federal self-employment tax savings dwarf the 1.5% California charge. But the calculation is tighter here than in a no-tax state, and running the numbers for California specifically is essential. This is current as of October 3, 2026. Tax laws change frequently, so verify with the IRS or California Franchise Tax Board if you are reading this later.

Frequently Asked Questions

Can I change my entity structure later?

Yes. One of the advantages of starting as an LLC is flexibility. You can elect S Corp status when your profit grows, and in some cases convert to a C Corp if you pursue outside investment. The structure is not permanent, though changing it does involve filing requirements and timing considerations.

Do I need an attorney to form an LLC or elect S Corp status?

Not necessarily. The filings themselves can be done without an attorney, but the strategic decision of which structure fits your income and goals benefits enormously from professional analysis. The cost of a wrong structure far exceeds the cost of getting advice up front.

Is an S Corp always better than a default LLC?

No. For businesses with low profit, inconsistent income, or losses, the added cost and complexity of running S Corp payroll can outweigh the self-employment tax savings. The S Corp wins at higher, consistent profit levels, generally above $60,000 in net income.

Will electing S Corp status increase my audit risk?

Only if you set an unreasonably low salary. A properly documented reasonable salary paired with clean payroll records keeps you fully compliant. The election itself does not raise your risk; aggressive salary manipulation does.

Book Your Entity Strategy Session

If you are running a profitable business as a default LLC, there is a real chance you are overpaying self-employment tax by thousands every year, and no one has shown you the math. Deciding between S Corp LLC or C Corp should never be a guess. Our strategy team will run your exact numbers, identify the structure that keeps the most money in your pocket, and handle the entire election and setup so you stay compliant. Click here to book your consultation now and walk away knowing precisely which entity saves you the most.