Self-Employment Tax Guide: What Sole Proprietors Need to Know

If you work for yourself — as a sole proprietor, freelancer, independent contractor, or single-member LLC owner — you are responsible for paying self-employment (SE) tax. This is the self-employed person's equivalent of the Social Security and Medicare taxes that employers and employees split in a traditional W-2 job. The difference is that you pay both halves.

Understanding how SE tax works, when it is due, and how to reduce it legally can save you thousands of dollars each year.

What Is Self-Employment Tax?

Self-employment tax covers your contributions to Social Security and Medicare. When you work as an employee, your employer withholds 7.65% from your paycheck and pays a matching 7.65% on your behalf. When you are self-employed, you pay the full 15.3% yourself.

The 15.3% breaks down as follows:

• Social Security: 12.4% on net self-employment income up to the annual wage base ($176,100 for 2026).
• Medicare: 2.9% on all net self-employment income with no cap.
• Additional Medicare Tax: An extra 0.9% on self-employment income exceeding $200,000 (single) or $250,000 (married filing jointly).

How to Calculate and Report SE Tax

Step 1: Determine Net Self-Employment Income

Start with your gross income from self-employment and subtract all allowable business expenses. If you are a sole proprietor or single-member LLC, this is your net profit from Schedule C (line 31). Partners use their share of partnership income from Schedule K-1.

Step 2: Apply the 92.35% Factor

The IRS allows you to multiply your net self-employment income by 92.35% (100% minus the 7.65% employer-equivalent deduction) before calculating SE tax. This mirrors the fact that employees do not pay FICA on the employer's share of FICA.

Step 3: File Schedule SE

Schedule SE is filed with your Form 1040 and calculates your total self-employment tax. You must file Schedule SE if your net self-employment income is $400 or more for the year.

Deducting Half of Self-Employment Tax

One important benefit: you can deduct the employer-equivalent portion of your SE tax (half of the total) as an adjustment to income on your Form 1040. This is an above-the-line deduction, which means you get it whether you itemize or take the standard deduction.

Using the example above, if your SE tax is $11,304, you can deduct $5,652 from your adjusted gross income. This reduces your income tax, though it does not reduce your SE tax itself.

Quarterly Estimated Tax Payments

Because no employer is withholding taxes from your income, the IRS requires self-employed individuals to make quarterly estimated tax payments using Form 1040-ES. These payments cover both your income tax and self-employment tax.

If you do not make sufficient estimated payments, the IRS will charge an underpayment penalty. The safe harbor rule says you can avoid this penalty by paying at least 100% of your prior year's tax liability (110% if your AGI exceeds $150,000) or 90% of the current year's liability, whichever is smaller.

Need help tracking these quarterly deadlines? A tool like BizTaxIntel sends reminders before each estimated payment is due.

How S-Corp Election Reduces Self-Employment Tax

One of the most common tax strategies for profitable sole proprietors is electing S-Corporation status. Here is how it works.

As a sole proprietor, your entire net business income is subject to the 15.3% SE tax. When you elect S-Corp status (by filing Form 2553 with the IRS), your business structure changes. Instead of all income being subject to SE tax, you split your income into two categories:

1. Reasonable salary: You pay yourself a W-2 salary that is subject to payroll taxes (the S-Corp equivalent of SE tax). This salary must be reasonable for the work you perform.
2. Shareholder distributions: Any remaining profits can be distributed to you as shareholder distributions, which are not subject to SE or payroll tax.

Example: S-Corp Savings

Suppose your business nets $120,000 per year.

• As a sole proprietor: You pay SE tax on the full $120,000, which is approximately $120,000 x 92.35% x 15.3% = $16,945.
• As an S-Corp: You pay yourself a reasonable salary of $60,000 and take $60,000 as a distribution. Payroll taxes apply only to the $60,000 salary: $60,000 x 15.3% = $9,180. The $60,000 distribution is not subject to payroll tax.
• Approximate savings: $16,945 - $9,180 = $7,765 per year.

S-Corp election also comes with additional compliance requirements, including payroll tax filings, a separate corporate return (Form 1120-S), and potential state annual report requirements. Make sure the tax savings justify the extra costs before making the switch.

Other Ways to Reduce SE Tax

• Maximize business deductions: Every dollar of legitimate business expense reduces your net income and your SE tax.
• Retirement contributions: Contributions to a SEP-IRA or Solo 401(k) reduce your taxable income (though not your SE tax base).
• Health insurance deduction: Self-employed individuals can deduct 100% of health insurance premiums as an adjustment to income.