Most business owners believe picking between a C corp and S corp is a paperwork decision their attorney handles once and forgets. That belief quietly costs them tens of thousands of dollars. The entity you sit inside decides how your profit gets taxed, whether your income gets hit twice, how much you pay in self-employment tax, and how big a check you write to California every April. This is not a filing formality. It is the single largest lever most owners have over their tax bill, and the wrong choice compounds year after year.

Here is the truth almost nobody explains in plain English: the C corp and S corp are not two versions of the same thing. They are two entirely different tax animals wearing similar legal clothing. Choose based on how much profit you keep, how you pay yourself, and where your business is headed, not on which one sounds more official. Below, we break down exactly how each is taxed, who wins with each structure, the real dollar math, and the mistakes that turn a smart election into an audit magnet.

Quick Answer: The Core Difference Between a C Corp and S Corp

A C corporation pays its own tax at a flat 21 percent federal rate, then shareholders pay tax again on any dividends they take. That is the famous double taxation. An S corporation is a pass-through entity, meaning profits skip corporate tax entirely and land directly on the owner’s personal return, taxed once. For most profitable small businesses in California, the S corp wins because it avoids the second layer of tax and slashes self-employment tax. The C corp shines for companies reinvesting heavily, raising venture capital, or offering rich tax-free fringe benefits.

The letters “C” and “S” simply refer to the subchapter of the Internal Revenue Code that governs how the entity is taxed. Both can be the same underlying corporation legally. The difference is a tax election, filed with the IRS, that flips how the money is treated.

How a C Corp Is Actually Taxed

A C corp is the default status for any corporation the moment it is formed. It is treated as a separate taxpayer from you. The company files its own return, Form 1120, and pays a flat 21 percent federal income tax on its profits. That rate has been fixed since the 2017 Tax Cuts and Jobs Act, and it applies for the 2026 tax year.

The Double Taxation Trap in Plain English

Here is where owners get burned. Say your C corp earns $200,000 in profit. The corporation pays 21 percent, or $42,000, leaving $158,000. If you then pay yourself that $158,000 as a dividend, you pay tax again on your personal return at the qualified dividend rate, which can reach 20 percent federally, plus the 3.8 percent net investment income tax for high earners. On top of that, California does not offer a preferential dividend rate, so the state taxes it as ordinary income up to 13.3 percent.

Stack it all up and the same dollar of profit can be taxed at a combined effective rate north of 40 percent before it reaches your personal bank account. That is the double taxation trap: once at the corporate level, once when it comes to you.

When the C Corp Structure Wins

Double taxation only stings when you pull money out. If you leave profit inside the company to fund growth, hire, or buy equipment, you only pay the flat 21 percent and defer the second layer indefinitely. That is why the C corp is a favorite for:

• Startups planning to raise venture capital or issue preferred stock
• Companies reinvesting nearly all profit back into operations
• Owners who want to sell qualified small business stock and potentially exclude up to $10 million in gain under Section 1202
• Businesses offering generous tax-free fringe benefits like full health reimbursement and life insurance to owner-employees

Key Takeaway: The C corp is a growth and reinvestment vehicle. If you are draining profit for personal income every year, it is usually the wrong home for your money.

How an S Corp Is Actually Taxed

An S corp does not pay federal income tax at the entity level. Instead, profit, losses, and deductions “pass through” to the owner’s personal return, reported on Schedule E via a Schedule K-1. You are taxed once, at your personal rate. That single fact eliminates the double taxation problem entirely.

The Self-Employment Tax Advantage

The bigger win for most owners is self-employment tax savings. A sole proprietor or single-member LLC pays 15.3 percent self-employment tax on every dollar of net profit up to the Social Security wage base, then 2.9 percent Medicare above it. An S corp owner splits income into two buckets: a reasonable salary, which is subject to payroll tax, and remaining profit as a distribution, which is not subject to self-employment tax at all.

Consider Marcus, a marketing consultant in San Diego netting $150,000. As a sole proprietor, he pays roughly $21,000 in self-employment tax. After electing S corp status and paying himself a reasonable $85,000 salary, payroll taxes apply only to that salary, saving him around $9,900 per year. That is real money, every single year, for a one-time election. If you want to run your own numbers, the self-employment tax calculator shows how much of your profit is currently exposed.

This is where business owners capture the most immediate savings. For a full breakdown of how S corp elections work under California rules, see our complete guide to S corp tax strategy in California.

The California S Corp Catch

California does not fully respect the federal pass-through treatment. The state imposes a 1.5 percent franchise tax on S corp net income, with an $800 annual minimum. So a California S corp earning $200,000 pays roughly $3,000 to the state at the entity level, on top of the owner’s personal tax. It still beats a C corp for most owners, but the 1.5 percent is a real cost you must factor into the math.

C Corp and S Corp Side by Side: The Numbers That Matter

Comparisons get abstract fast, so here is a clean breakdown of the factors that decide the outcome.

Notice the California line. A C corp pays 8.84 percent state tax on its net income, far above the S corp’s 1.5 percent. For a California business distributing profit to its owners, that gap alone often tips the scale toward the S corp before you even factor in the federal double taxation.

Should You Elect S Corp Status? A Simple Decision Framework

Use these criteria to gut-check your situation before you file anything.

An S corp likely fits if:

• Your business nets more than $60,000 in profit annually
• You can justify and pay yourself a reasonable market salary
• You are pulling most profit out for personal income
• You are a US citizen or resident with fewer than 100 owners

A C corp likely fits if:

• You are reinvesting nearly all profit back into the business
• You plan to raise outside investment or issue multiple stock classes
• You want to eventually sell qualified small business stock for the Section 1202 exclusion
• You want to offer robust tax-free fringe benefits to owner-employees

If your answers land in the S corp column, our entity formation services can handle the election and set up your payroll correctly the first time.

KDA Case Study: LLC Consultant Restructures to an S Corp

Priya, a 1099 IT consultant in Sacramento, operated as a single-member LLC netting $175,000 per year. She came to KDA frustrated after her prior preparer told her “an LLC is fine, don’t overthink it.” What that advice missed was the $23,000 in self-employment tax she was handing the IRS annually on profit that could have been partially shielded.

We ran the analysis and elected S corp status by filing Form 2553 with a reasonable compensation study to back her salary. We set her salary at $95,000, supported by regional market data for senior consultants, and treated the remaining $80,000 as a distribution not subject to self-employment tax. We also set up compliant payroll and quarterly deposits to keep her clean with both the IRS and the FTB.

The result: Priya saved approximately $10,400 in the first year on self-employment tax alone, even after accounting for California’s 1.5 percent franchise tax and the added payroll cost. She paid KDA $3,500 for the restructure and first-year compliance work, a first-year return of roughly 3x, with the savings repeating every year going forward. More importantly, her salary was defensible, so the strategy would survive scrutiny.

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.

The Reasonable Salary Trap That Triggers Audits

Here is the mistake that turns a brilliant S corp strategy into an IRS nightmare: paying yourself too little salary to dodge payroll tax. The IRS requires S corp owner-employees to take “reasonable compensation” for the work they perform. If you net $200,000 and pay yourself a $20,000 salary while taking $180,000 as a distribution, you have painted a target on your return.

The IRS has won numerous cases reclassifying distributions as wages, then hitting owners with back payroll taxes, penalties, and interest. In the well-known Watson v. United States case, a CPA who paid himself $24,000 while taking $200,000 in distributions was forced to reclassify $91,000 as wages.

How to Set a Defensible Salary

1. Research market rates for your role using sources like the Bureau of Labor Statistics or salary surveys.
2. Document the analysis in writing and keep it in your files.
3. Factor in your actual duties, hours worked, and experience level.
4. Split reasonably, so your salary is defensible relative to total profit, not a token amount.

Red Flag Alert: A salary that is a tiny fraction of your total profit is the fastest way to lose the entire benefit in an audit. When in doubt, err toward a higher, well-documented salary. Our tax planning services include reasonable compensation studies that hold up under scrutiny.

Can I Switch From an S Corp Back to a C Corp?

Yes, but not casually. You can revoke an S election, and you can convert a C corp to an S corp, but the IRS imposes a five-year waiting period before you can re-elect S status after revoking it, absent special consent. There are also built-in gains tax traps when converting from C to S if the company holds appreciated assets. This is not a switch to flip on a whim, which is exactly why the initial choice matters so much.

What If My Business Loses Money?

Structure matters here too. In an S corp, losses pass through to your personal return and can offset other income, subject to basis and at-risk rules. In a C corp, losses stay trapped inside the entity as a net operating loss carryforward, useful only when the company becomes profitable. If you expect early losses and have other income to shelter, the pass-through S corp offers an immediate benefit the C corp cannot.

How Do I Actually Make the Election?

To elect S corp status, you file Form 2553 with the IRS. The timing is strict.

1. File within 75 days of forming the entity or by March 15 for the election to apply to the current tax year.
2. Get all shareholders to sign the consent portion of the form.
3. Set up payroll before you take any distributions, so your salary flows correctly.
4. Make quarterly estimated payments to both the IRS and the FTB to avoid underpayment penalties.

Miss the deadline and you may be stuck as a C corp or sole proprietor for the year, though late election relief exists in some cases with reasonable cause.

Frequently Asked Questions

Is an S corp always better than a C corp for small businesses?

No. For profitable small businesses that distribute earnings to owners, the S corp usually wins by avoiding double taxation and cutting self-employment tax. But if you are reinvesting profit, raising capital, or planning for a Section 1202 stock sale, the C corp can be the smarter long-term play.

Does an LLC change this comparison?

An LLC is a legal structure, not a tax classification. An LLC can be taxed as a sole proprietorship, partnership, C corp, or S corp. Many owners form an LLC and then elect S corp taxation to get liability protection plus pass-through tax savings.

How much profit justifies an S corp election?

As a rough rule, once your net profit clears roughly $60,000 to $80,000 and you are paying meaningful self-employment tax, the savings usually outweigh the added payroll and compliance costs. A quick analysis with a professional confirms the break-even for your specific numbers.

What is the biggest S corp mistake owners make?

Underpaying their reasonable salary to dodge payroll tax. It saves money on paper but invites reclassification, penalties, and interest if the IRS reviews the return.

Book Your Entity Strategy Session

Choosing between a C corp and S corp is not a coin flip, and the wrong pick quietly drains thousands from your business every year you stay in it. If you are unsure whether your current structure is costing you money, or whether your salary split will survive an audit, let us run the actual numbers for your situation. Book a personalized consultation with our strategy team and walk away knowing exactly which entity keeps more money in your pocket, and how to make the election correctly. Click here to book your consultation now.

This information is current as of 9/29/2026. Tax laws change frequently. Verify updates with the IRS or FTB if reading this later.