Self-employment tax — the bill nobody withholds for you

When you work for yourself—as a freelancer, consultant, small-business owner, or independent contractor—no employer takes taxes from your paychecks. That means you must plan for and pay three separate taxes: regular income tax, self-employment tax for Social Security and Medicare, and, in most states, state income tax. This article focuses on self-employment tax, the one most people are caught off guard by because they did not know it existed.

What is self-employment tax?

Self-employment tax covers your Social Security and Medicare contributions. When you work as an employee, your employer withholds 7.65% of your paycheck: 6.2% for Social Security and 1.45% for Medicare. The employer also pays another 7.65% on your behalf. As a self-employed person, you pay both halves yourself—a total of 15.3%. This is separate from your regular income tax.

You owe self-employment tax only if your net self-employment earnings are $400 or more in a year. The 15.3% rate breaks down into 12.4% for Social Security (only on earnings up to an annual cap) and 2.9% for Medicare (on all earnings with no cap). In 2026, the Social Security cap is $184,500. Earnings above that cap still owe Medicare tax, but not the Social Security portion.

Why the IRS expects quarterly payments, not a lump sum in April

The US tax system operates on what the IRS calls "pay as you go." When employees work, their employer withholds taxes from every paycheck and sends them to the IRS throughout the year. The IRS expects the same from self-employed people—but without an employer to do the withholding, you must make estimated tax payments four times a year instead of once in April.

The quarterly deadlines for 2026 are April 15, June 15, September 15, and January 15, 2027. Each payment covers income earned in roughly three-month periods, though the periods are not equal (the second quarter covers only April and May, for example). If a due date falls on a weekend or federal holiday, the deadline moves to the next business day.

How to calculate and pay your quarterly estimated tax

To find your quarterly payment, estimate your total net self-employment income for the year, subtract business expenses, and divide by four. You can use IRS Form 1040-ES, which includes a worksheet to help you. If your income is uneven (some months earn much more than others), you may use an annualized method to reduce overpayment in slow months.

You can pay online through IRS Direct Pay at pay.irs.gov with no fee, or through EFTPS (Electronic Federal Tax Payment System) if you enroll in advance. Some people use credit or debit card processors, though these charge a convenience fee of roughly 1.85%. You can also print Form 1040-ES with a payment voucher and mail it to the IRS.

Deductions that lower your self-employment tax bill

Your self-employment tax is calculated on your net earnings, meaning your gross income minus legitimate business expenses. The lower your net earnings, the lower your self-employment tax. This is where tracking expenses carefully pays off. You report business deductions on Schedule C of Form 1040.

Home office deduction

If you use part of your home exclusively and regularly for business, you may claim a home office deduction. There are two methods: the simplified method and the regular method. The simplified method lets you deduct $5 per square foot of office space, capped at 300 square feet (maximum $1,500 per year). The regular method deducts a percentage of your rent, mortgage interest, utilities, insurance, and repairs based on the office's share of your home's total square footage. You must choose one method and stick with it for the year.

Mileage and vehicle expenses

If you drive for your business—client meetings, supply runs, deliveries—you can deduct mileage at the IRS standard rate ($0.725 per mile in 2026). This single number covers gas, insurance, maintenance, and depreciation. Track the date, destination, miles, and business purpose of each trip. Alternatively, you can deduct actual vehicle expenses (gas, repairs, insurance, depreciation) but this is more complicated and usually yields less benefit than the standard mileage rate.

Supplies, equipment, and software

Office supplies (pens, notebooks, paper), software subscriptions, computers, phones, and equipment used for your business are all deductible. The key is that the item must be ordinary and necessary for your work. Keep receipts and buy in the year you use the items—the IRS will not accept a claim that you used six months' worth of supplies in one week to save on taxes.

Health insurance premiums

If you are self-employed and pay your own health insurance premiums, you can deduct 100% of the cost. This is deducted on Form 1040, not on Schedule C, and helps reduce your adjusted gross income (AGI). Self-employed health insurance is separate from your business expenses and gives you an extra tax benefit.

Other common deductions

• Advertising and marketing (business cards, website, social media, online ads)
• Professional services (accountant, lawyer, bookkeeper fees)
• Rent or lease for office space outside your home
• Telephone and internet bills (allocate the business percentage)
• Postage and shipping supplies
• Training courses, certifications, and conferences related to your trade
• Subscriptions to industry publications or tools

The silver lining: You can deduct half your self-employment tax

Here is one advantage of self-employment: you can deduct half of the self-employment tax you pay when calculating your adjusted gross income (AGI). This does not reduce the self-employment tax itself, but it reduces your income tax. For example, if you owe $10,000 in self-employment tax, you deduct $5,000 from your income when filing Form 1040. This deduction applies only to the Social Security portion of the tax (12.4%), which is then paired with the Medicare portion (2.9%), creating the full 15.3% tax. After filing, you claim the half-deduction on Form 1040 line 15.

This matters for retirement planning as well. Even though you pay self-employment tax, those payments earn you Social Security credits toward future benefits. When you retire, your Social Security check will be based on your lifetime earnings and contributions, including the years you were self-employed.

What to avoid and how to stay compliant

Self-employment tax is mandatory if you earn $400 or more in net profit. You cannot escape it by calling yourself a "business consultant" instead of an employee, by being paid in cash, or by claiming you are still on a temporary visa. The IRS looks at the substance of your work, not your visa status or how you describe your role. This is true for all visa holders—whether you are on an F-1 student visa, an H-1B work visa, a green card, or a work authorization (EAD or ITIN).

Many immigrants and visa holders worry about reporting self-employment income to the IRS. Reporting income does not change your immigration status. In fact, filing taxes is expected of all workers in the US, and a clean tax record helps you if you later apply for a green card or citizenship. Employers and government agencies may ask to see your tax returns as proof of legitimate, declared income.

Common questions about self-employment tax for immigrants and visa holders

Do I need a Social Security Number to pay self-employment tax?

No. If you do not have a Social Security Number (SSN), you can use an Individual Taxpayer Identification Number (ITIN). An ITIN is a nine-digit tax ID issued by the IRS to people who are required to file a US tax return but are not eligible for an SSN. You apply for an ITIN on Form W-7 and can file your taxes and pay self-employment tax with it. An ITIN does not grant you work authorization, but it allows you to comply with US tax law.

If I have both W-2 income and self-employment income, do I owe self-employment tax?

Yes. If your net self-employment earnings are $400 or more, you owe self-employment tax regardless of whether you also have a job. However, your employer's W-2 withholding may cover some or all of your estimated tax liability for the year. If you have both sources of income, track them carefully and may want to file adjusted Form W-4 with your day job to increase your withholding, which can reduce the amount you owe in estimated quarterly payments.

What if I earn money while on a student visa?

On an F-1 student visa, you may be permitted to work on campus, for an authorized off-campus employer, or as part of an Optional Practical Training (OPT) program. Employment outside these categories can affect your visa status. Always check with your international student advisor before starting any work. However, if you do work legally and earn $400 or more in net self-employment income, you must file taxes and pay self-employment tax. Using an ITIN instead of violating visa work restrictions is the lawful option.

Key takeaways

1. Self-employment tax is 15.3% (12.4% Social Security + 2.9% Medicare) on 92.35% of your net self-employment earnings. It is separate from income tax, and you owe both.
2. You must pay four times a year—April 15, June 15, September 15, and January 15—not in one lump sum in April. Missing a deadline triggers penalties and interest even if you pay in full later.
3. Deduct all legitimate business expenses: home office, mileage, supplies, health insurance, and professional services. The lower your net earnings, the lower your self-employment tax.
4. You can deduct half of your self-employment tax from your adjusted gross income, and those payments earn you Social Security credits toward retirement.
5. Use Form 1040-ES to estimate your quarterly payment, and file IRS Form 1040 with Schedule SE when you file your annual return. Pay online through IRS Direct Pay or EFTPS to avoid mailing delays.
6. Report your income honestly. Filing taxes does not change your immigration status and is legally required for all workers in the US, regardless of visa type.