Sole Proprietorship vs. LLC vs. S-Corp: Which Entity Structure Saves the Most Tax?

By Yarik Yarosh, CPA ·September 5, 2026 ·Updated September 23, 2026 ·14 min read

Written by Yarik Yarosh, CPA (US & Canada) September 5, 2026 · FL CPA license AC61704 · CPA Ontario

New business owners consistently ask: “What entity should I choose?” The question implies that the entity structure itself drives tax savings. In reality, the sole proprietorship and single-member LLC produce identical federal tax results. The tax savings come from the S-Corp election, which any LLC (or corporation) can make by filing Form 2553.

✓Key takeaway

Side-by-side comparison at three income levels:

$40,000 net profit:

	Sole Prop / LLC	S-Corp ($30,000 salary)
SE / payroll tax	$5,652	$4,590 + admin
Compliance cost	$0-$800	$2,000-$4,000
Net savings from S-Corp	N/A	-$938 to -$2,938 (LOSS)
Verdict	Stay sole prop	Not worth it

$80,000 net profit:

	Sole Prop / LLC	S-Corp ($50,000 salary)
SE / payroll tax	$11,304	$7,650
Compliance cost	$0-$800	$2,000-$4,000
Net savings from S-Corp	N/A	$654-$2,654
Verdict	Borderline	Break-even to modest savings

$150,000 net profit:

	Sole Prop / LLC	S-Corp ($70,000 salary)
SE / payroll tax	$21,190	$10,710
Compliance cost	$0-$800	$2,000-$4,000
Net savings from S-Corp	N/A	$7,480-$9,480
Verdict	Leaving money on table	Clear S-Corp winner

The break-even point is approximately $50,000-$60,000 in net profit. Below that, the S-Corp compliance costs consume the SE tax savings.

What exactly does the S-Corp change?

The S-Corp doesn’t change what’s taxable. For current guidance, see IRS LLC guidance. It changes HOW it is taxed. A sole proprietor pays self-employment tax (15.3%) on ALL net profit. An S-Corp owner pays payroll taxes (15.3%) only on the reasonable salary, and the remaining pass-through profit avoids SE/payroll tax entirely.

The “reasonable salary” requirement is the constraint: the IRS requires S-Corp owners who perform services to pay themselves a salary that would be reasonable for an unrelated person doing the same work. Setting the salary too low (to maximize SE tax savings) triggers reclassification of distributions as wages, with back taxes, penalties, and interest.

The QBI deduction under IRC 199A interacts with the entity choice but is available to all three structures. The calculation differs slightly: for sole proprietors and LLC owners, QBI equals the net profit minus the deductible portion of SE tax. For S-Corp owners, QBI equals the K-1 pass-through income (which is net profit minus the reasonable salary).

At higher income levels (above $191,950 single / $383,900 MFJ in 2024), the QBI deduction is limited by W-2 wages paid (for non-SSTBs). An S-Corp that pays W-2 wages has an advantage here: the owner’s salary counts as W-2 wages for the QBI limitation, while a sole proprietor has no W-2 wages.

When does a C-Corp make sense?

A C-Corporation is taxed at a flat 21% corporate rate, with dividends taxed again to shareholders (double taxation). At most income levels this costs more than the S-Corp. The C-Corp becomes advantageous in three situations:

1. QSBS exclusion (IRC 1202). If the business is a C-Corp from inception, the stock is held for 5+ years, and the business is a qualified small business (under $50 million in gross assets), the owner can exclude up to $10 million (or 10x basis) of capital gain on the sale. On a $5 million exit, that exclusion saves approximately $1,190,000 in federal capital gains tax. This only works for C-Corps, never for S-Corps.

2. Retained earnings at 21%. If the owner’s personal marginal rate exceeds 21% and the business retains earnings for reinvestment rather than distributing them, the corporate rate is lower. This is common for businesses building cash reserves, purchasing real estate, or funding R&D.

3. Outside investors. Venture capital and institutional investors typically require a C-Corp structure (preferred stock, liquidation preferences, convertible notes).

C-Corp comparison at $120,000 net profit (single filer):

Corporate tax (21%): $25,200
If remaining profit distributed as $60,000 salary + dividends on the rest: approximately $32,382 total tax
Compare to S-Corp at the same income: approximately $20,416 total tax
The C-Corp costs roughly $12,000 more per year at this income level

Decision framework:

Net Profit	Recommendation
Under $50,000	Sole prop or LLC (disregarded)
$50,000-$70,000	Evaluate S-Corp (depends on compliance costs, state fees)
Over $70,000	S-Corp almost always saves money
Any level, planning $1M+ exit	Evaluate C-Corp for QSBS
Seeking outside investors	C-Corp (VCs prefer it)

How is the self-employment tax calculated?

Self-employment tax is 15.3% on net self-employment income up to the Social Security wage base ($168,600 in 2024), then 2.9% on income above that threshold. Net self-employment income is calculated as 92.35% of your Schedule C net profit (the 7.65% reduction approximates the employer-half FICA deduction that W-2 workers receive). You deduct half of the self-employment tax on Schedule 1 of Form 1040, which reduces your AGI and income tax but does not reduce the SE tax itself. The additional Medicare tax of 0.9% applies to combined wages and self-employment income exceeding $200,000 ($250,000 married filing jointly). This makes the effective rate on high-income self-employment earnings 16.2%.

Related guides:

Industry-specific entity guides:

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Cite this page

Yarik Yarosh, CPA. "Sole Proprietorship vs. LLC vs. S-Corp: Which Entity Structure Saves the Most Tax?." Blue Cloud CPA, September 5, 2026, updated September 23, 2026. https://bluecloudcpa.com/guides/small-business-llc-sole-prop-scorp-comparison

This guide is general information, not tax advice for your specific situation. Which points apply, and how, depends on your facts.