C-Corp vs S-Corp: Which Structure Saves You More in Taxes

Most small business owners I talk to have already made up their mind before they even ask the question. They’ve read somewhere that S-corps are “better for taxes” or that C-corps are “only for big companies,” and they want me to confirm what they’ve already decided. I’ll be honest: that’s usually the wrong starting point, and getting this choice wrong can cost you real money over a period of years, not a rounding error.

I spent a good chunk of time last year going back through client files, specifically looking at cases where the entity choice turned out to be the wrong one. What surprised me was how often the mistake wasn’t made out of ignorance. It was made with incomplete information from someone who understood part of the picture but not all of it.

So let’s actually look at this, from the inside out.

The tax structure nobody actually draws out

Here’s the core difference, stripped of everything else. A C-corp is its own taxpayer. It pays federal corporate income tax (currently a flat 21% at the federal level) on its profits. If it distributes those profits to shareholders as dividends, those shareholders pay tax again, at rates up to 23.8% including the net investment income tax. That’s what people mean by double taxation. It’s real, and it hurts if you’re a small operation pulling money out regularly.

An S-corp, by contrast, is a pass-through. The company itself doesn’t pay federal income tax. Profits flow through to the shareholders’ personal returns, and you pay tax once, at your individual rate. For a profitable small business owner in a high tax bracket, this can be a significant difference in actual dollars owed each year.

But here’s where I’ve seen people get it wrong, including me early in my career: the S-corp advantage isn’t unlimited. If you’re retaining a lot of earnings inside the company to fund growth, the C-corp’s 21% rate is actually lower than what most individual owners would pay at the pass-through level. A business owner in the 37% individual bracket passing through $400,000 in profits pays roughly $148,000 in federal income tax on that money. A C-corp pays $84,000. The gap closes or reverses if you eventually distribute that money, but if you’re reinvesting indefinitely, the math shifts.

Worked example: A software founder retaining $500,000 annually for product development chooses C-corp status → pays 21% federal on retained earnings ($105,000) vs. pass-through S-corp rate of 37% ($185,000) → saves $80,000/year in tax while growth phase lasts.

The ownership and investor rules that will box you in

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This is the section most articles bury, and it shouldn’t be buried, because this is often the deciding factor.

S-corps have hard restrictions baked in. You can have no more than 100 shareholders. Every single one must be a U.S. citizen or permanent resident. You cannot have another corporation or an LLC as a shareholder. And you get one class of stock, period. No preferred shares, no different dividend rights, no liquidation preferences.

If you ever want outside investment from a venture fund, a family office, or almost any institutional source, those investors will want preferred stock. Preferred stock is how they protect themselves in a downside scenario. An S-corp structurally cannot give them what they want, which means the moment you accept that kind of investment, your S-corp election gets blown up anyway. I’ve seen founders scramble to convert at exactly the wrong time because they hadn’t planned for this.

C-corps, particularly Delaware C-corps, were essentially designed for investment. Multiple stock classes, no shareholder count limits, no residency requirements, foreign shareholders welcome. If there’s any realistic scenario where you raise a funding round in the next five years, start as a C-corp. The U.S. Small Business Administration (SBA) has solid guidance on entity selection if you want the government’s plain-language take, though I’d still recommend talking to a CPA who specializes in small business before you file anything.

Side-by-side: the numbers that matter

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One thing that table doesn’t capture: state taxes. Not every state conforms to the federal S-corp pass-through treatment. California, for instance, charges S-corps a 1.5% franchise tax on net income, with a $800 minimum. If you’re in a state with its own corporate tax regime, do that math specifically for your location before deciding.

The self-employment tax angle (it’s more nuanced than the internet suggests)

You’ve probably read that S-corps save you on self-employment tax. This is true, but often overstated.

With an S-corp, you’re required to pay yourself a “reasonable salary” for the work you do. That salary is subject to payroll taxes (Social Security and Medicare, totaling 15.3% up to the wage base, and 2.9% above it). Profits above your salary pass through without the SE tax hit.

So if your business nets $200,000 and you pay yourself a reasonable salary of $90,000, you pay payroll taxes on $90,000 and avoid SE tax on the remaining $110,000. At roughly 15.3% on that $110,000, that’s about $16,800 in savings. Real money. But you have to maintain payroll, file quarterly payroll tax returns (Form 941), potentially hire a payroll service like Gusto ($46/month at their current base plan as of mid-2026), and deal with more administrative overhead than you’d have as a sole proprietor.

The IRS scrutinizes S-corp reasonable salary aggressively. Setting your salary at $30,000 while pulling $300,000 in distributions is a red flag and an audit target. I’ve watched this go badly for clients who thought they were being clever.

Worked example: A consultant earning $180,000 net converts to S-corp, sets $80,000 reasonable salary → saves approximately $15,300 in SE tax annually → minus $552 in Gusto fees, minus CPA costs of roughly $1,200-$2,500/year for the added complexity → net benefit in the $12,000-$13,000 range, still worth it at that income level.

When converting is a trap

Here’s the scenario I see play out more than I’d like. A business starts as a C-corp, builds up value, and then wants to switch to S-corp to get the pass-through treatment. The IRS has a rule specifically for this: if an S-corp sells assets that were appreciated while the company was a C-corp, those gains (called “built-in gains”) are subject to corporate-level tax for a period of five years after conversion. So you convert, think you’re now a pass-through entity, sell a piece of equipment or intellectual property that appreciated years ago, and suddenly face a surprise 21% corporate tax on the gain before it even gets to your personal return.

This is not widely understood, and it’s caught people off guard. The lesson: make the right choice at formation if you can.

SCORE’s mentorship program (score.org) is underutilized for exactly this kind of structural planning. They connect you with experienced CFOs and business attorneys who can give a real-world sanity check on your situation before you commit to a structure.

Worked example: A founder converts C-corp to S-corp with $300,000 in built-in appreciated assets → sells those assets 18 months post-conversion → still owes corporate-level tax of $63,000 on the gain → lesson: the 5-year clock matters and should factor into any conversion timeline.

Sources

• IRS S Corporation Tax Center: Official IRS guidance on S-corp elections, Form 2553, and shareholder rules
• IRS Corporate Tax Rate Information: Current 21% federal corporate flat rate and filing requirements for C-corps
• U.S. Small Business Administration (SBA) Entity Selection Guide: Plain-language comparison of business structures
• Delaware Division of Corporations: Why Delaware remains the preferred state of incorporation for investor-backed C-corps
• IRS Publication 542: Corporations: Detailed guidance on corporate tax rules, distributions, and built-in gains rules for converting entities

Photo: cottonbro studio via Pexels

This article is for general informational purposes only and does not constitute financial, tax, or legal advice. Business finance and tax rules vary by entity type, state, and individual circumstances. Consult a qualified CPA, enrolled agent, or business attorney for advice specific to your situation.

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