Self-Employed Tax Basics

The first April after going self-employed is a reckoning for most people. Not because they were reckless, but because nobody explained that becoming self-employed doesn't just change how you work — it fundamentally changes how taxes are collected, who pays both sides of the payroll tax, and why your effective tax rate is higher than it was when you were an employee even if your income is identical.

The surprise isn't income tax — people understand that exists. The surprise is self-employment tax: 15.3% on net self-employment income, on top of income tax. Employees pay 7.65% of their wages toward Social Security and Medicare, and their employer pays a matching 7.65%. When you're self-employed, you are both the employee and the employer. You pay both halves. On a net income of $80,000, that's $12,240 in self-employment tax before a dollar of income tax is calculated.

Understanding what's coming is most of the battle. The people who get hit hardest are the ones who treated all their revenue as income available to spend, didn't set money aside throughout the year, and opened a tax bill in April with nothing to cover it.

Quarterly estimated taxes — why they exist and what happens when you skip them

Employees have taxes withheld from every paycheck. The government gets its money throughout the year in small installments. Self-employed people have no withholding — nothing is taken out before the money arrives. The IRS addresses this by requiring quarterly estimated tax payments, due in April, June, September, and January.

If you don't make quarterly payments and owe more than $1,000 when you file, the IRS charges an underpayment penalty. The penalty rate is roughly 8% annualized on the underpaid amount — not a catastrophic number, but an avoidable one. More importantly, skipping quarterly payments means a very large bill in April, which is the situation that causes the most financial stress for self-employed people.

There are two safe-harbor methods for calculating quarterly payments that avoid penalties. The simpler one: pay 100% of last year's tax liability in equal quarterly installments (110% if your prior year income exceeded $150,000). You may still owe more in April if this year's income was higher, but no penalty applies. The more accurate method: estimate this year's actual income and pay 90% of the projected tax quarterly. This requires more tracking but produces a more accurate year-end number.

What you can actually deduct

Business deductions reduce your net self-employment income, which reduces both your income tax and your self-employment tax. Every dollar of legitimate deduction saves you roughly 25 to 40 cents depending on your tax bracket — the higher your income, the more each deduction is worth.

The home office deduction is available if you use a part of your home regularly and exclusively for business. Exclusively is the key word — the IRS is strict about this, and a desk in your bedroom that you also use for personal computing doesn't qualify. A dedicated room used only for work does. You can calculate the deduction using the simplified method ($5 per square foot, up to 300 square feet) or the regular method (a percentage of actual home expenses equal to the percentage of your home used for business).

Health insurance premiums are fully deductible for self-employed individuals — you can deduct 100% of premiums paid for yourself and your family from your gross income. This deduction is taken on Schedule 1 of Form 1040, not on Schedule C, and it reduces income tax but not self-employment tax. Still, for someone paying $600 a month for family health coverage, that's $7,200 a year in deductible premiums.

Other deductible business expenses include software and subscriptions used for work, professional development and education, equipment (computers, cameras, tools), business travel, mileage driven for business purposes (67 cents per mile in 2024), and professional services like accounting and legal fees. The standard for deductibility is that the expense is ordinary and necessary for your type of business.

Retirement accounts — the largest legal tax reduction available

Self-employed people have access to retirement accounts with higher contribution limits than employees get through a standard 401(k). A SEP-IRA allows contributions of up to 25% of net self-employment income, with a 2024 maximum of $69,000. Every dollar contributed reduces your taxable income by a dollar. On $100,000 of net self-employment income, maxing a SEP-IRA contribution of $18,587 (roughly 25% after accounting for the SE tax deduction) saves approximately $4,600 in income tax for someone in the 25% bracket, plus reduces the SE tax base slightly.

A Solo 401(k) — also called an individual 401(k) — allows both employee and employer contributions as a self-employed person. The employee contribution limit is $23,000 in 2024 (with a $7,500 catch-up if you're 50 or older), plus an employer contribution of up to 25% of compensation, up to the same $69,000 combined ceiling. For self-employed people with higher incomes who want to shelter more than a SEP-IRA allows at lower income levels, the Solo 401(k) is usually the better vehicle.

Contributing to a retirement account is the most powerful tax reduction tool available to self-employed people. It reduces current-year taxes, builds long-term wealth, and the money grows tax-deferred until withdrawal. Every self-employed person who isn't contributing to a SEP-IRA or Solo 401(k) is leaving a significant tax break on the table.

Recordkeeping — the unglamorous part that saves the most money

The IRS requires documentation for every business deduction. A deduction you can't substantiate with records is a deduction you'll lose in an audit. For most self-employed people, the recordkeeping system doesn't need to be complicated — a dedicated business bank account and credit card, a folder of digital receipts, and a mileage tracking app are sufficient.

The most common recordkeeping failure is mixing personal and business expenses. Running personal purchases through a business account — or business purchases through a personal account — creates confusion, makes tax preparation harder, and raises questions in an audit. A separate business checking account and business credit card, used exclusively for business, eliminates most of this problem. The cost is one extra account. The benefit is clean records that take hours to reconcile at tax time instead of days.

Mileage is one of the most commonly under-documented deductions. At 67 cents per mile, business mileage adds up quickly — 5,000 business miles a year is a $3,350 deduction. The IRS requires contemporaneous records: mileage logs that document the date, purpose, and distance of each business trip. Apps like MileIQ or Stride automatically track and categorize mileage, removing the friction of manual logging.

The practical tax reserve — what percentage to set aside

A practical starting point for tax reserves: set aside 25% to 30% of every payment received into a separate savings account designated for taxes. The right percentage depends on your income level, deductions, and state income tax — but 25% to 30% covers the combined federal income tax and self-employment tax for most people earning between $50,000 and $150,000 in net self-employment income.

That money should sit in a high-yield savings account earning interest until the quarterly payment dates. It shouldn't be accessible for other spending. Many self-employed people find that treating the tax reserve as already spent — not available money — removes the temptation to borrow from it for other purposes.

Self-employment doesn't come with a tax department that handles the paperwork. It comes with the same tax obligations, repackaged as your responsibility. Knowing the obligations before the first April makes every subsequent year manageable instead of a crisis.