Entity Structure Optimization: LLC vs. S-Corp vs. C-Corp

1. Separate the legal wrapper from the tax election

"LLC vs. S-corp" is a category error: an LLC is a legal entity; S and C are tax classifications. An LLC can be taxed as a disregarded entity, a partnership, an S corporation, or a C corporation. The legal wrapper drives liability and governance; the election drives tax. Most optimization work is about changing the election, not re-forming the company.

2. Default LLC / sole proprietor taxation

Simple and flexible: profit flows to your return, losses may be usable, and distributions are unrestricted. The cost is self-employment tax on the entire profit (15.3% up to the Social Security wage base, then Medicare portions above it). California adds the $800 annual LLC tax plus a gross-receipts fee that starts at $250,000 of revenue — a fee on revenue, not profit, which stings low-margin businesses.

3. The S election: the payroll-tax play, with strings

An S corporation splits owner income into reasonable W-2 compensation (payroll-taxed) and distributions (not payroll-taxed). The savings are real once profits meaningfully exceed a defensible salary — as a rough screen, we start modeling seriously around $80–100K of consistent net profit. The strings:

• Reasonable compensation is not optional. A token salary is the most audited number in the small-business world, and it also caps your retirement plan contributions, which are salary-based.
• California levies a 1.5% franchise tax on S corporation net income (minimum $800) — a real cost to include in the model that generic calculators skip.
• Eligibility is strict: one class of stock, 100 or fewer shareholders, and no nonresident alien or entity shareholders. Cross-border cap tables usually disqualify the election entirely — see our foreign-owned entity guide.
• QBI interplay: the Section 199A deduction is computed after wages; the salary/distribution split changes the deduction, so the "optimal" salary is a joint optimization, not a rule of thumb.

4. The C corporation: flat rate, two layers, and QSBS

C corporations pay a flat 21% federal rate (California: 8.84%), and shareholders pay again on dividends — the famous double tax. So why choose it? Three honest reasons: venture financing (investors and option pools expect it), profit retention (reinvesting at 21% beats top personal rates), and QSBS — Section 1202 can exclude substantial gain on qualified small business stock held five years, which for eligible startups can dominate every other consideration in the analysis. The wrong reason: parking personal income in a C corporation to defer tax invites accumulated earnings and personal holding company problems.

5. The California PTET overlay

For pass-throughs (S corporations and partnerships), California's pass-through entity elective tax lets the entity pay state tax at 9.3% and hand owners a credit — a workaround for the federal SALT deduction cap. Whether it pays depends on the owners' situations and requires a timely election and June prepayment, so it belongs on the annual planning agenda, not an afterthought at filing.

6. How we run the comparison

1. Model 2–3 years of projected profit under each structure — federal, CA, SE/payroll tax, QBI, PTET — side by side.
2. Stress the "reasonable comp" assumption against your industry data.
3. Price the switching costs: payroll setup, additional returns, S election timing, built-in gains where relevant.
4. Check the exit: asset vs. stock sale treatment and QSBS eligibility under each path.