C Corp vs S Corp vs LLC: Key Differences and How to Choose the Right Structure

Key Takeaways

A C corp is taxed as a separate entity. Profits are taxed at the corporate level and again when distributed to shareholders as dividends. Delaware C corps are the standard for venture-backed startups.
An S corp passes income through to shareholders who pay tax at their individual rate. It avoids double taxation but has strict eligibility restrictions: 100 shareholders maximum, one class of stock, and all shareholders must be US citizens or residents.
An LLC is flexible: it can be taxed as a sole proprietorship, partnership, S corp, or C corp depending on elections made. It offers liability protection with less administrative burden than a corporation.
If you plan to raise venture capital, incorporate as a C corp. VCs require preferred stock, which S corps cannot issue.
Converting from S corp to C corp after incorporation is possible but creates legal costs and potential tax consequences. Getting the structure right at formation is significantly cheaper.

What Is a C Corp?

A C corporation is a business entity taxed as a separate legal entity from its owners. The corporation pays corporate income tax on profits. When those profits are distributed to shareholders as dividends, shareholders pay personal income tax on the distributions. This is the double taxation that C corps are frequently criticized for.

The corporate income tax rate is currently a flat 21% at the federal level. The trade-off for double taxation is flexibility: a C corp can have unlimited shareholders, multiple classes of stock including preferred stock, foreign shareholders, and no restrictions on who can invest.

Delaware C corps are the default entity structure for technology startups seeking venture capital because they are well-understood by investors and supported by a mature body of corporate law.

What Is an S Corp?

An S corporation is a corporation that has elected pass-through taxation with the IRS. Instead of paying corporate income tax, the S corp passes its profits and losses through to shareholders who report them on their personal tax returns. This eliminates the double taxation problem of a C corp.

The primary appeal of an S corp for business owners is the self-employment tax savings. Shareholders who work in the business pay themselves a reasonable salary, which is subject to payroll taxes. Remaining distributions are not subject to self-employment tax.

The trade-off is strict eligibility requirements: an S corp is limited to 100 shareholders, can only have one class of stock, and all shareholders must be US citizens or permanent residents. These restrictions make S corps incompatible with institutional investment.

What Is an LLC?

A Limited Liability Company (LLC) is a flexible entity structure that provides personal liability protection without the formality of a corporation. By default, a single-member LLC is taxed as a sole proprietorship and a multi-member LLC is taxed as a partnership. Both are pass-through structures.

An LLC can also elect to be taxed as an S corp or C corp if the eligibility requirements are met. This makes the LLC the most structurally flexible option, particularly for small businesses and professional service firms that do not need corporate governance structure or outside equity investment.

C Corp vs S Corp vs LLC: Key Differences

C corp vs S corp vs LLC compared across key dimensions for founders choosing a business entity structure
Feature	C Corp	S Corp	LLC
Taxation	Double taxation: corporate + dividend	Pass-through to shareholders	Pass-through by default, flexible
Shareholder limit	Unlimited	100 maximum	Unlimited members
Stock classes	Multiple (common + preferred)	One class only	Flexible via operating agreement
Foreign ownership	Allowed	US citizens/residents only	Allowed
VC fundraising	Standard structure	Not compatible	Possible but atypical
Self-employment tax	N/A for shareholders	Savings on distributions	Depends on tax election
Admin burden	High: board meetings, filings	Medium: corporate formalities	Low
Best for	Startups seeking investment	Profitable small businesses, no outside equity	Service businesses, flexibility seekers

The Fundraising Decision That Most Founders Learn Too Late

This is the information that changes the entity decision for founders with any intention of raising outside capital.

Venture capital investors invest through preferred stock. Preferred stock gives investors priority in liquidation, anti-dilution protections, and other rights that common stockholders do not have. An S corp can only issue one class of stock. The moment you issue preferred stock to an investor, your S corp election is terminated automatically by the IRS.

Most VC term sheets also include institutional investors, foreign entities, or investment funds as shareholders. S corps cannot have any of these as shareholders. A single non-qualifying shareholder terminates the S election.

The practical result: if you form an S corp intending to raise venture capital, you will convert to a C corp before or during your first institutional round. That conversion involves legal fees, potential state filings, and in some cases a built-in gains tax if the business has appreciated assets from the S corp period that are subsequently sold within five years of conversion.

Forming a Delaware C corp from the start costs the same as forming an S corp and eliminates the conversion cost entirely. For founders who know they want to raise capital, the S corp election makes the self-employment tax savings a temporary benefit with a deferred structural cost.‍

When to Choose Each Structure

Choose a C corp when:

You plan to raise venture capital or angel investment
You want to issue stock options to employees through an equity incentive plan
You expect foreign shareholders or institutional investors
You are building a business intended for acquisition by a larger company

Choose an S corp when:

The business is profitable and owner-operated with no plans for outside equity
The primary goal is reducing self-employment tax on owner distributions
You have fewer than 100 shareholders who are all US citizens or residents
You are not issuing multiple stock classes or preferred equity

Choose an LLC when:

You want maximum flexibility with minimum administrative burden
The business is a professional services firm, partnership, or real estate holding entity
You want the option to elect S corp or C corp taxation without full corporate formality
You are in an early stage and want to preserve optionality before committing to a corporate structure

For founders on the fence between S corp and C corp at the early stage, the tax savings from an S corp election are real but the structural limitations create deferred costs that frequently exceed the savings. Consult a CPA or tax attorney who works with early-stage companies before making the final decision.

What Entity Structure Means for Your Books

Regardless of which entity you choose, the financial infrastructure underneath the business needs to be clean from day one. C corps, S corps, and LLCs all need accurate books to support tax filings, investor reporting, and business decisions.

For founders running on QuickBooks Online, entity structure affects how payroll, distributions, and equity transactions are recorded but not whether clean books matter. Founders who have already connected QuickBooks Online and Stripe for real-time revenue visibility can produce accurate financial statements regardless of entity type when reporting is needed. And since C corps specifically face stricter financial reporting requirements as they raise capital, automating the month-end close becomes more important at each fundraising stage when investors ask for historical financials on short timelines.

Finlens runs on top of QuickBooks Online with no migration and automates the categorization and reconciliation that keeps financial statements accurate and audit-ready regardless of which entity structure the business uses.

Before Finlens: Close the books manually each month, produce financial statements when investors ask, and scramble to reconcile months of transactions for a due diligence request.

After Finlens: Books close cleanly every period. Financial statements are always current. Investor due diligence requests get answered from data that is already accurate.

The C corp vs S corp vs LLC decision is one of the most consequential early choices a founder makes. The entity you choose determines your tax structure, your fundraising options, and the cost of changing your mind later. Getting the books right inside whatever entity you choose is what makes everything downstream cleaner.

FAQ

What is the difference between a C corp and S corp?

‍A C corp is taxed as a separate entity and can have unlimited shareholders and multiple stock classes. An S corp passes income to shareholders who pay personal tax but is limited to 100 US shareholders and one class of stock. C corps are standard for venture-backed startups. S corps work for profitable owner-operated businesses with no outside equity.

What is the difference between a C corp and an LLC?

‍A C corp has a defined corporate structure with shareholders, directors, and officers, and is taxed as a separate entity. An LLC is more flexible, with members instead of shareholders, and pass-through taxation by default. LLCs have less administrative overhead but may not be the right structure for businesses seeking venture capital.

Can an S corp become a C corp?

‍Yes. An S corp can convert to a C corp by revoking its S election. The conversion involves legal filings and may trigger a built-in gains tax on appreciated assets sold within five years of conversion. The conversion is manageable but costs money and time that could have been avoided by forming a C corp originally.

Why do VCs require a C corp?

‍VCs invest through preferred stock, which requires multiple stock classes. S corps can only issue one class of stock. A single preferred stock issuance automatically terminates an S corp election. VCs also invest through funds and entities that are not eligible S corp shareholders.

Is an LLC better than an S corp?

‍For early-stage businesses with no plans for institutional investment, an LLC provides more flexibility and less administrative burden than an S corp. For profitable businesses where reducing self-employment taxes is the primary goal, an S corp election on an LLC or standalone S corp may be advantageous. The right answer depends on the business model, ownership structure, and growth plans.

What is the tax advantage of an S corp over a C corp?

‍An S corp avoids double taxation by passing income directly to shareholders who pay personal income tax. It also allows owner-employees to split compensation between salary, which is subject to payroll taxes, and distributions, which are not. A C corp pays corporate income tax on profits and shareholders pay personal income tax on dividends.