Sole Proprietor vs. LLC vs. S-Corp: Which Business Structure Saves the Most in Taxes?

One of the most common questions freelancers ask once they start earning serious money: "Should I form an LLC or S-corp to save on taxes?" The answer depends on your income level, your state, and whether the administrative costs justify the savings.

Here's how each structure is taxed and at what income level each one makes financial sense.

Default Tax Treatment by Entity Type

Sole Proprietor

If you freelance without any formal business structure, you're a sole proprietor by default. Your business income is reported on Schedule C (attached to your personal Form 1040), and you pay:

• Federal income tax on your net profit, at your marginal bracket
• Self-employment tax: 15.3% on the first $176,100 of net SE earnings (for 2025; the 2026 wage base will be announced later), then 2.9% above that

The self-employment tax consists of Social Security (12.4%) and Medicare (2.9%), the same taxes W-2 employees pay. You cover both the employee and employer halves because you're both.

You can deduct the employer-equivalent half (7.65%) of SE tax as an above-the-line deduction on Schedule 1.

Net effect: On $100,000 of profit, you pay roughly $14,130 in SE tax plus federal income tax on ~$92,935 after the SE deduction.

Single-Member LLC

A single-member LLC (SMLLC) is a disregarded entity for federal tax purposes by default. It's taxed exactly the same as a sole proprietor: Schedule C, same SE tax, same everything. The LLC provides liability protection (your personal assets are legally separate from business debts and lawsuits) but zero tax difference without making an election.

If you form an LLC solely to save taxes without electing S-corp status, you've paid legal formation fees for a structure that's identical to a sole proprietorship from the IRS's perspective.

S-Corporation

An S-corp is a separate legal entity that passes its income through to shareholders' personal returns. What makes it different from a sole proprietorship or LLC is how the income is split:

Part 1 - Salary: As an owner-employee, you must pay yourself a reasonable salary for the work you do. This salary is subject to payroll taxes (Social Security and Medicare) at the standard W-2 rate.

Part 2 - Distribution: Any profit above your salary can be taken as a shareholder distribution, and distributions are not subject to SE tax or payroll taxes.

This is the S-corp tax advantage in a nutshell: you pay payroll taxes only on your salary, not on the full business profit.

The S-Corp Savings Math

Let's compare a freelancer earning $150,000 net profit under each structure:

As a sole proprietor/single-member LLC:

• SE tax (approximate): ~$18,228 (15.3% on first $176,100 x 92.35%)
• Deductible half of SE tax: ~$9,114
• Taxable income: ~$140,886

As an S-corp (salary $70,000, distribution $80,000):

• Payroll taxes on salary: $70,000 x 15.3% = $10,710 (split employer/employee)
• Distribution: $80,000, no SE tax
• Net payroll tax savings: ~$7,518

At $150,000 of income, the S-corp saves roughly $7,500 per year in payroll taxes. That sounds compelling, but you need to offset it against the real costs of running an S-corp.

S-Corp Costs: What Eats Into the Savings

Formation and state fees: Forming a corporation or converting your LLC to be taxed as an S-corp costs $500 to $1,500 in legal and filing fees depending on your state.

Annual state fees: Many states charge minimum franchise taxes or annual fees for corporations. California charges a minimum $800 franchise tax per year regardless of income. Delaware, New York, and Illinois have their own fee structures.

Payroll administration: You must run a formal payroll, withhold taxes, and make quarterly payroll tax deposits. A payroll service like Gusto or ADP costs $500 to $1,500 per year for a single-person S-corp.

Separate tax return: S-corps file Form 1120-S, a separate corporate return, in addition to your personal 1040. CPA fees for preparing both returns run $1,000 to $3,000+ annually, compared to $300 to $800 for a sole proprietor return.

State income taxes: Some states don't recognize S-corp status and tax the entity at the corporate level anyway (New York City, for example, imposes a city tax on S-corps).

Total annual overhead: $2,000 to $6,000+ per year is realistic for running a properly structured S-corp.

The Break-Even Point

Given typical S-corp overhead of $3,000 to $4,000 per year, the savings from reduced payroll taxes need to exceed that amount for the structure to make sense.

A common rule of thumb: the S-corp election rarely pays off below $80,000 to $100,000 in net profit. At lower income levels, the overhead exceeds the tax savings. At higher income levels ($200,000+), the savings grow significantly.

Rough savings estimates at different income levels:

Net Profit	Estimated SE Tax Savings (S-corp vs. sole prop)	Typical S-Corp Overhead	Net Benefit
$60,000	~$2,000	$3,000 to $4,000	Likely negative
$100,000	~$4,500	$3,000 to $4,000	Marginal ($500 to $1,500)
$150,000	~$7,500	$3,000 to $4,000	Meaningful ($3,500 to $4,500)
$200,000	~$9,200	$3,000 to $4,000	Strong ($5,200 to $6,200)

Note: These are approximations. Actual savings depend on your state taxes, the reasonable salary amount you set, and your specific expenses. Work with a CPA to model your situation.

The "Reasonable Salary" Problem

The IRS requires S-corp owner-employees to pay themselves a salary that's "reasonable" for the services they perform. If you're a software developer billing $200,000 per year and paying yourself a salary of $31,500, the IRS will likely argue your salary should be higher, reducing the distribution amount and the associated tax savings.

There's no exact formula, but courts and the IRS look at:

• What similar employees in your field earn
• Your hours worked and the complexity of the work
• What you'd pay someone else to do what you do
• Industry salary data

Setting a salary that's too low is one of the most common S-corp audit triggers. A well-structured S-corp typically sets salary at 40 to 60% of total compensation for service businesses.

When to Make the Switch

If you're consistently netting $100,000+ and your income is stable enough to justify the administrative overhead, the S-corp election makes financial sense. The process:

1. Form a corporation or convert your existing LLC to a corporation in your state
2. File Form 2553 with the IRS to elect S-corp tax treatment (must be filed within 75 days of the start of the tax year you want it to take effect, or by March 15 for the current year in many cases)
3. Set up payroll and begin paying yourself a reasonable salary
4. File Form 1120-S annually and issue yourself a W-2

If you're not yet at the income threshold, the single-member LLC is typically the right structure. It gives you liability protection at low cost and keeps your taxes simple.

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WriteOff helps you track your Schedule C income and expenses year-round so you always know your net profit, the key number for deciding whether an S-corp makes sense for your situation.

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Sources

• IRS Choosing a Business Structure - Tax treatment of each entity type
• IRS S Corporations - S-corp requirements and tax treatment
• IRS Single Member LLC - Default disregarded entity treatment
• IRS Form 2553: S-Corp Election - March 15 deadline for S-corp election

An LLC is a state-law entity with no federal tax category of its own. It is taxed as a disregarded entity, partnership, or corporation depending on elections made. Source: Treas. Reg. § 301.7701-3.