How to Register a US Company: LLC vs C-Corp Tax and Liability Differences

Deciding between an LLC and a C-Corp is one of the first major decisions for anyone registering a US company, affecting both tax liability and personal asset protection. According to the IRS, as of 2024, there were over 22 million pass-through entities (including LLCs) filing tax returns in the US, compared to roughly 1.9 million traditional C-Corporations, highlighting the popularity of simpler structures [IRS 2024, Tax Statistics]. The choice hinges on two core factors: how the business is taxed and the level of legal protection for its owners. An LLC (Limited Liability Company) offers pass-through taxation, meaning profits are taxed only at the owner’s personal income tax rate, which can be as high as 37% for top earners in 2025 [IRS 2025, Revenue Procedure 2024-40]. A C-Corp, conversely, is taxed as a separate entity at a flat 21% corporate rate, but shareholders also face a second tax on dividends, creating the “double taxation” scenario. Liability-wise, both structures shield personal assets from business debts, but the C-Corp’s stricter formalities—like mandatory board meetings and annual reports—provide a stronger corporate veil. This guide breaks down the tax and liability differences across five key areas to help you choose the right structure for your US company registration.

LLC Taxation: Pass-Through Mechanics and Self-Employment Tax

The defining feature of LLC taxation is its status as a “pass-through entity.” The LLC itself does not pay federal income tax. Instead, all profits and losses “pass through” to the individual members’ personal tax returns (Form 1040, Schedule C or E). This avoids the double taxation problem inherent in C-Corps.

For single-member LLCs, the IRS treats the entity as a “disregarded entity” for tax purposes unless the owner elects otherwise. Multi-member LLCs file an informational partnership return (Form 1065) but still pass income through to members via Schedule K-1. The downside is that all net earnings are subject to self-employment tax (Social Security and Medicare), which totals 15.3% on the first $176,100 of net earnings in 2025, plus 2.9% on amounts above that [Social Security Administration 2025, Fact Sheet]. This can significantly reduce net income for active business owners.

H3: Electing S-Corp Status for an LLC

An LLC can elect to be taxed as an S-Corporation by filing Form 2553 with the IRS. This allows the owner to pay themselves a “reasonable salary” (subject to payroll taxes) and take remaining profits as distributions, which are not subject to self-employment tax. This strategy can save thousands of dollars annually for businesses with net incomes above roughly $60,000, but requires payroll setup and compliance.

C-Corp Taxation: Double Taxation and the Flat 21% Rate

A C-Corp taxation structure creates a separate tax-paying entity. The corporation pays federal corporate income tax at a flat 21% rate (permanent since the Tax Cuts and Jobs Act of 2017). When the corporation distributes profits to shareholders as dividends, those dividends are taxed again at the shareholder’s individual capital gains rate (0%, 15%, or 20%, depending on income). This is the classic double taxation problem.

However, the C-Corp offers advantages for reinvestment. Retained earnings (profits kept in the business) are only taxed at the corporate rate, allowing the company to accumulate capital for growth without immediate personal tax consequences. C-Corps can also deduct the full cost of health insurance premiums for employees (including owner-employees), which is more restrictive for LLC members. For startups planning to raise venture capital or eventually go public, the C-Corp structure is almost always required by investors.

H3: Accumulated Earnings Tax and Personal Holding Company Tax

C-Corps that retain earnings beyond reasonable business needs may face an accumulated earnings tax of 20% on excess retained earnings (IRC § 531). Similarly, a personal holding company tax of 20% applies if too much income comes from passive sources. These penalties are designed to prevent C-Corps from hoarding profits to avoid shareholder dividend taxes.

Liability Protection: The Corporate Veil and Formalities

Both LLCs and C-Corps provide limited liability protection, meaning owners are generally not personally responsible for business debts or lawsuits. However, the strength of this corporate veil depends on how well the entity is maintained. Courts can “pierce the veil” if owners treat the business as their personal piggy bank.

For C-Corps, the formalities are strict: annual shareholder meetings, board of directors meetings, corporate minutes, separate bank accounts, and proper issuance of stock. Failure to follow these can lead to personal liability. LLCs have fewer statutory requirements but still require a separate operating agreement, separate bank accounts, and clear records. In practice, LLC owners often operate more informally, which can increase risk in a lawsuit.

H3: State-Level Variations in Liability

Some states offer additional liability protection. For example, Delaware’s Court of Chancery has extensive case law on corporate veil piercing, making it a preferred state for incorporation. Wyoming and Nevada offer strong asset protection for LLCs, including charging order protection (preventing a creditor from seizing an owner’s interest in the LLC). The choice of state matters significantly for liability outcomes.

Formation and Compliance Costs: State Fees and Annual Requirements

Forming an LLC is generally cheaper and simpler than forming a C-Corp. Most states charge between $50 and $500 for LLC formation, while C-Corp filings can range from $100 to $1,000 depending on the state. Annual compliance costs also differ: LLCs typically pay annual report fees of $50 to $800, while C-Corps face higher costs due to franchise taxes and more complex filings.

For example, California charges an $800 annual franchise tax for both LLCs and C-Corps, plus a gross receipts fee for LLCs that can reach $11,790 [California FTB 2025, Publication 1060]. Delaware imposes a franchise tax on C-Corps based on authorized shares or assumed par value capital, which can be minimal for startups but significant for larger companies. For international founders, using a service like Sleek AU incorporation can streamline the process of setting up a US entity remotely, though they primarily focus on Australian incorporation—for US-specific needs, consult a registered agent service.

H3: IRS Employer Identification Number (EIN)

Both structures require an EIN from the IRS for tax purposes, bank accounts, and hiring employees. The application is free online via the IRS website and typically takes minutes to complete.

Investor Appeal and Exit Strategy: Why VCs Prefer C-Corps

For startups seeking venture capital, the C-Corp structure is virtually mandatory. Venture capital firms invest in C-Corps because they can issue multiple classes of stock (common, preferred, Series A, etc.), which LLCs cannot easily replicate. C-Corps also allow for employee stock option plans (ESOPs) that are tax-advantaged and standard in the startup ecosystem.

Exit strategies like an IPO or acquisition are also smoother with a C-Corp. Public markets require C-Corp status, and acquirers prefer the clean corporate structure. LLCs can convert to C-Corps before an exit, but this conversion triggers taxable events and legal costs. According to the National Venture Capital Association, over 98% of venture-backed startups in the US are structured as C-Corps [NVCA 2024, Yearbook].

FAQ

Q1: Can I change my LLC to a C-Corp later?

Yes. An LLC can convert to a C-Corp by filing Form 8832 (Entity Classification Election) with the IRS. However, the conversion is treated as a taxable event—the LLC’s assets are deemed sold to the new corporation at fair market value, potentially triggering capital gains tax. The process also requires state-level filings and legal fees. Most startups plan for this conversion at the time of their first institutional funding round.

Q2: Which structure has lower annual compliance costs?

For a small, single-owner business with revenue under $100,000, an LLC is almost always cheaper. Annual compliance costs for an LLC typically range from $100 to $800 (state fees plus registered agent). A C-Corp can cost $500 to $2,000 annually due to franchise taxes, annual report filings, and the need for corporate minutes. However, for high-income businesses, the C-Corp’s 21% tax rate may offset higher compliance costs.

Q3: Does an LLC protect personal assets from lawsuits?

Yes, an LLC provides limited liability protection, meaning personal assets (home, car, personal bank accounts) are generally shielded from business debts and lawsuits. However, this protection is not absolute. If the LLC is undercapitalized, used for personal expenses, or operated without a separate bank account, a court can pierce the veil. Maintaining proper records and a separate operating agreement is essential.

References

• IRS 2024, Tax Statistics – Pass-Through Entities vs C-Corporations Filing Data
• IRS 2025, Revenue Procedure 2024-40 – Individual Tax Rate Brackets
• Social Security Administration 2025, Fact Sheet – Self-Employment Tax Rates
• California Franchise Tax Board 2025, Publication 1060 – Annual Franchise Tax and Gross Receipts Fee
• National Venture Capital Association 2024, NVCA Yearbook – Startup Structure Preferences