They aren’t two different companies. They’re the same corporation taxed under two different chapters of the tax code, and choosing between them shapes everything from your tax bill to how you raise money.
- S corporation (Subchapter S, elected): profit passes through and is taxed once, on the owners’ returns, in exchange for strict ownership limits. No more than 100 US shareholders, one class of stock, Form 1120-S.
- C corporation (Subchapter C, the default): pays its own tax, and shareholders pay again on dividends, but with no limits on who can own it. Unlimited shareholders, multiple stock classes, Form 1120.
Here’s the part that trips up almost every founder: an S corp and a C corp are not two different kinds of company. They’re the same legal entity, a corporation formed under state law, taxed under two different chapters of the Internal Revenue Code. The letters come straight from those chapters: Subchapter C and Subchapter S. So the real question is rarely “which company should I form?” It’s “how do I want that corporation taxed?” If you’re one step earlier in the decision, our guide to choosing between an LLC and a corporation is the better place to start.
The short answer: A C corporation is the default. It pays 21% federal income tax on its profit, and shareholders pay again on dividends, the “double taxation” you’ve heard about. An S corporation elects pass-through treatment by filing Form 2553, so profit is taxed only once, on the owners’ returns. In return it accepts strict limits: no more than 100 shareholders, only US individuals and certain trusts, estates and tax-exempt organizations as owners, and a single class of stock. Neither is better for everyone; the answer depends on how you pay yourself, whether you’ll raise outside capital, and how much profit you keep in the business.
Key takeaways
- Tax elections, not business types: you form one corporation, then choose how it is taxed.
- One layer or two: a C corp is taxed at the entity level and again on dividends; an S corp is taxed once.
- S corp limits: up to 100 shareholders, eligible US owners only, one class of stock.
- C corp freedom: no ownership limits and preferred stock, which is why venture and IPO paths run through C corps.
- Form 2553: elect S status within 2 months and 15 days of the tax year; do nothing and you are a C corp.
- Salary rule: S corp owners who work in the business must take a reasonable salary.
First, the Thing Most People Get Wrong
When you file articles of incorporation with the state, you create a corporation, full stop. The state does not know or care whether you will be an “S corp” or a “C corp”, because that distinction is purely a federal tax matter. Unless you take a further step, the IRS treats the new corporation as a C corporation and taxes it under Subchapter C.
To be taxed as an S corporation instead, the corporation files Form 2553 (Election by a Small Business Corporation) with the IRS, signed by every shareholder, no later than 2 months and 15 days after the start of the tax year it should apply to, and it must meet every Subchapter S eligibility rule. That is the whole mechanism. Same entity, same liability shield, same articles of incorporation: one form and a set of restrictions separate the two tax worlds. You can read more on our C corporation and S corporation pages.
What the Two Actually Share
Because an S corp and a C corp are the same underlying entity, most of what you think of as “being a corporation” is identical on both sides.
- Limited liability: shareholders are not personally liable for business debts either way.
- Separate legal entity: the corporation exists in its own right, created by a state filing.
- Same formation documents: articles of incorporation are filed with the state whatever the tax election.
- Same governance: shareholders, a board, officers, bylaws, meetings, a registered agent and annual state filings apply to both.
Take all of that away and only a few things are left: how you are taxed, who can own the company, what stock you can issue, and how easily you can raise money.
Not sure which election fits your plans?
Our CPA team walks founders through the S vs. C decision every week, factoring in how you pay yourself, your investors and your growth path.
How Each One Is Taxed: The Heart of the Decision
C Corp: Taxed Twice, but Flexible
A C corp is a separate taxpayer. It files Form 1120 and pays 21% federal income tax on its profit. When it pays out what is left as dividends, shareholders pay tax again on their personal returns, at up to 20% on qualified dividends plus the 3.8% net investment income tax for higher earners. Salaries paid to owner-employees are deductible to the company, so only profit paid as dividends is taxed twice.
S Corp: Taxed Once, Straight Through
An S corp files Form 1120-S, but that return is mainly informational; the company generally pays no federal income tax. Profits and losses pass through on Schedule K-1 to the owners’ personal returns, where the tax is paid, whether or not the cash is distributed. Owners who work in the business must take a reasonable salary through payroll; profit above that salary is not subject to payroll tax. Many owners can also deduct up to 20% of their share of qualified business income.
Worked Example: $200,000 of Profit, Fully Paid Out
A corporation earns $200,000 of profit (after the owner’s salary) and the owner wants to take it all out. Federal tax only, using illustrative rates:
| C corp | S corp | |
|---|---|---|
| Corporate tax on $200,000 at 21% | $42,000 | None |
| Left for the owner | $158,000 as a dividend | $200,000 on the owner's return |
| Owner's tax | $23,700 (qualified dividend at 15%) | Income tax at the owner's rates, less any qualified business income deduction |
| Total federal income tax | $65,700 (about 33%) | Depends on the owner's bracket; taxing it all at 24% after the full 20% QBI deduction gives about $38,400 |
Top-Rate Comparison
| C corp | S corp | |
|---|---|---|
| Profit paid out as dividends | 21% + (79% × 23.8%) = 39.8% | 37% × 80% = 29.6% (if the full QBI deduction applies) |
| Profit kept in the business | 21% | Up to 37% (29.6% with QBI), even though no cash was paid out |
For a business that pays out most of its profit to a small group of owners, the S corp’s single layer of tax is often cheaper. For one that reinvests heavily, plans to raise venture capital, or keeps profit inside the company, the C corp’s 21% rate on retained earnings and its flexibility can outweigh the second layer. State taxes, the type of business (some service businesses get a reduced QBI deduction) and how you pay yourself all change the answer, which is why entity choice sits upstream of every other tax question; see our guide to the main types of business taxes.
One Choice, a Chain of Consequences
The S vs. C election looks like a single checkbox, but it sets your tax bill, who can invest, what stock you can issue, and how easily owners can come and go. That is why it pays to decide deliberately rather than default into it.
S Corp vs. C Corp, Side by Side
Even when the tax math favors an S corp, the eligibility rules can take it off the table. Read this as a filter, not just a list.
| C corporation | S corporation | |
|---|---|---|
| Tax treatment | Taxed at the entity level at 21%; dividends taxed again to shareholders | Pass-through; profit taxed once on the owners' returns |
| Federal return | Form 1120 | Form 1120-S, plus a Schedule K-1 for each shareholder |
| How you get it | Default; no election needed | File Form 2553, signed by all shareholders, within 2 months and 15 days of the start of the tax year |
| Shareholder limit | Unlimited | No more than 100 (members of a family can count as one) |
| Who can own shares | Anyone: individuals, companies, funds and non-US persons | US citizens and residents, certain trusts and estates, and certain tax-exempt organizations |
| Classes of stock | Multiple (common, preferred and others) | One class (differences in voting rights allowed) |
| Raising venture capital | The standard structure | Effectively ruled out; most funds cannot be shareholders |
| Losses | Stay in the company as net operating losses | Pass through to owners, limited by basis and other rules |
| Owner pay | Salary (deductible) and dividends (not deductible) | Reasonable W-2 salary required for working owners; remaining profit as distributions free of payroll tax |
| Profit kept in the business | Taxed at 21% | Taxed to the owners whether or not distributed |
| Sale of stock | Qualified small business stock may be partly or fully tax-free under Section 1202 | No Section 1202 exclusion |
If you need preferred stock, plan to raise a venture round, or expect a non-US or entity owner on the cap table, Subchapter S is usually out and a C corp is the practical answer. Foreign-owned C corps also file Form 5472 each year. If ownership is a small group of US individuals sharing profit in proportion to their shares, the S corp’s single layer of tax is often the better result.
The Advantages and Trade-Offs
S Corporation
Where it shines
- One layer of tax. Profit is taxed only on the owners’ returns.
- Payroll tax savings. Distributions above a reasonable salary are not subject to payroll tax.
- Losses can flow to you. They can offset an owner’s other income, within basis and other limits, which helps in lean years.
Where it limits you
- 100-shareholder cap. Cannot go public; limited reach for equity.
- Narrow list of owners. Eligible US owners only, which shuts out most venture and private equity funds.
- One class of stock. No preferred shares or special distribution rights, and profit must be split strictly by ownership.
- Transfer restrictions. Shareholder agreements usually limit transfers to protect the election, which can make exits clumsier.
- Tax on undistributed profit. Owners pay tax on their share even if the company keeps the cash.
C Corporation
Where it shines
- No ownership limits. Unlimited shareholders, including companies and non-US investors.
- Multiple stock classes. Issue the preferred and other share classes investors want.
- Built for raising capital. The structure venture funds expect and the one needed for an IPO.
- 21% on retained profit. Lower than top individual rates while the company reinvests.
- Section 1202. Shareholders in a qualifying company may exclude some or all of the gain when they sell their stock.
Where it limits you
- Double taxation. Profit paid as dividends is taxed at the corporate level and again on the shareholder’s return.
- Losses stay inside. Early losses cannot offset the owners’ other income.
How to Choose: Signals That Point Each Way
Lean Toward an S Corp If
- Your owners are a small group of US individuals.
- You plan to pay out most of the profit rather than keep it.
- You don’t expect to issue preferred stock or take institutional investment.
- Pass-through treatment lowers the owners’ total tax, or early losses would help on personal returns.
Lean Toward a C Corp If
- You plan to raise venture capital or eventually go public.
- You want to reinvest and keep earnings inside the company.
- You need multiple classes of stock or freely transferable shares.
- Your cap table will include companies, funds or non-US owners.
Once the tax election is settled, the next questions are usually where to incorporate and how to set up cleanly; our US company registration service can help.
Entity Decisions, Made with Confidence
We help founders and owners pick the right election and keep it compliant year after year.
- US CPA-led: advice based on current IRS rules, not generic templates.
- Filings done right: from the Form 2553 election to Form 1120 or 1120-S returns, prepared on time by our business tax team.
- The whole lifecycle: incorporation, the S election, conversions, financing and exit.
- Clear, current guidance: plain-English answers that keep up with changes in the tax rules.
Choosing Between an S Corp and a C Corp? Start with the Right Advice.
Countsure helps founders and small business owners pick the tax election that fits their ownership, payout plans and growth path, and keeps the filings that follow clean and on time.
Frequently Asked Questions
1. Is an S corp or a C corp better for a small business?
Neither is better for everyone. For a small, closely held business that pays out most of its profit to a few US owners, an S corp’s single layer of tax is often cheaper. For a company that plans to raise venture capital, keep most of its profit to reinvest, or go public, a C corp usually makes more sense despite the second layer of tax.
2. What is the main difference between an S corp and a C corp?
Tax. A C corp pays 21% federal tax on its profit, and shareholders pay tax again on dividends. An S corp passes profit through to its owners’ returns, where it is taxed once. S corps also have ownership and stock rules that C corps do not: no more than 100 shareholders, only eligible US owners, and one class of stock.
3. Can an LLC be an S corp or a C corp?
Yes. An LLC can elect to be taxed as an S corp (Form 2553) or a C corp (Form 8832) without changing its legal form. Many small businesses form an LLC and elect S corp tax for the pass-through treatment and payroll tax savings. The election changes how the LLC is taxed, not what it is.
4. How do I become an S corporation?
Form a corporation or LLC with your state, get an EIN, then file Form 2553, signed by every shareholder, no later than 2 months and 15 days after the start of the tax year the election should take effect. You must meet every eligibility rule. Without the election, a corporation is taxed as a C corp.
5. Why can't an S corp have venture capital investors?
S corps can only be owned by US individuals, certain trusts and estates, and certain tax-exempt organizations, and they can have only one class of stock. Most venture funds are partnerships, which cannot own S corp shares, and they expect preferred stock, which an S corp cannot issue. That is why venture-backed companies are almost always C corps.
6. Can I switch from a C corp to an S corp later?
Usually, if the corporation meets the eligibility rules, by filing Form 2553. A former C corp can owe built-in gains tax if it sells appreciated assets within five years, and may face tax on excess passive income if it has old C corp earnings. An S corp can also revoke its election to become a C corp, but it then generally has to wait five years to elect S status again.
7. Do S corp owners have to take a salary?
Yes, if they work in the business. Owner-employees must be paid a reasonable salary through payroll before taking distributions. Distributions above that salary are not subject to payroll tax, which is the main source of S corp tax savings, and setting the salary too low is a common audit issue.
Related Countsure Blogs
- What Is an S Corporation?: eligibility, Form 2553 and how S corps work.
- How to Form a C Corp: incorporation steps and yearly filings.
- LLC vs Corporation: the decision one step earlier.
- What Is an LLC?: how LLCs can elect S or C corp tax.
Parth Shah, Managing Director
(CPA-US, FCA, RV-S&FA, DISA)
Parth Shah who is head of Accounts and Book keeping has experience of more than 10 years. A Certified Public Accountant – US, fellow Chartered Accountant, Registered Valuer and Diploma in Information System Audit.
