Self-employment tax: what it is and how to plan for it
If you’ve ever looked at your tax bill as a self-employed person and thought "wait, that seems like a lot" — you are not imagining it. Self-employment tax is significant, and it catches a lot of new business owners completely off guard.
Here is what it is, why it exists, and what you can actually do about it.
What is self-employment tax?
When you work for an employer, Social Security and Medicare taxes get split between you and your employer. Each of you pays 7.65%. It shows up on your pay stub called something like “FICA tax” and you probably never think about it much.
When you work for yourself, there is no employer to split it with. You pay both halves. That means a 15.3% tax on your net self-employment income, on top of whatever income tax you owe.
For most self-employed people, this is the single biggest tax surprise of year one.
Who pays it?
If you are a sole proprietor, a single-member LLC, or a partner in a partnership, self-employment tax applies to your net business income. That means your revenue minus your business expenses. The 15.3% rate applies to the first $184,500 of net earnings (2026 figure, the cap gets adjusted each year). Above that threshold, only the 2.9% Medicare portion continues, with no cap.
If you have organized as an S-corp, the calculation works differently — but that is a topic for another post.
One deduction that softens the blow
A small bit of good news: the IRS lets you deduct half of your self-employment tax when calculating your income tax.
This deduction is calculated on Schedule SE and flows automatically to your Form 1040. Your tax software or CPA handles it, but it is worth knowing it exists.
How to plan for it
The most important thing you can do is stop thinking of all your revenue as money you get to keep. A portion of every dollar you earn is already spoken for… by the tax man.
A rough rule of thumb: set aside 25 to 30% of your net income for federal taxes if you are in a moderate income range. That covers both self-employment tax and income tax for most people, though your specific number depends on your total income, deductions, filing status, and state taxes.
Quarterly estimated taxes
The IRS expects self-employed people to pay taxes as they earn, not just at year end. That means making estimated tax payments four times a year. Missing these can result in underpayment penalties, even if you pay everything you owe by the filing deadline.
The due dates are generally:
April 15 (Q1)
June 16 (Q2)
September 15 (Q3)
January 15 of the following year (Q4)
You can make payments directly through the IRS at irs.gov/payments. Most people use EFTPS (Electronic Federal Tax Payment System) or pay directly by debit when the quarter is due.
Most tax software generates estimated tax vouchers — usually labeled 1040-ES — with the payment amounts and due dates already calculated based on your prior year liability. If you received these and ignored them (like most people do), now is a good time to dig them out and take a look. They are not mandatory to use but they give you a ready-made starting point for your quarterly payments.
How much should you pay each quarter?
This is where people get tripped up. You have two options and understanding both is worth your time.
Option 1: Pay based on what you actually earned. Calculate your estimated tax liability each quarter based on your actual income and expenses for that period. This is the most accurate method but requires you to run the numbers every quarter. If your income is variable, this approach means your payments fluctuate with your earnings, which can improve cash flow in slower quarters.
Option 2: Use the safe harbor rule. This is the option that lets you sleep at night. If you pay at least 100% of last year's total tax liability in equal quarterly installments, the IRS will not penalize you for underpaying — even if you end up owing more at year end. If your adjusted gross income last year was over $150,000, that threshold bumps up to 110% of last year's tax bill.
The safe harbor method is especially useful if your income has grown significantly year over year, or if your income is hard to predict. You are not guessing what you will owe this year, you are just paying what you already know you owed last year, spread across four quarters. Whatever you owe above that amount gets settled when you file.
The tradeoff is that if you had a much higher income year, safe harbor payments may leave you with a larger balance due in April than you were expecting. That is not a penalty situation, but it can be a cash flow surprise if you have not been setting money aside.
Which method should you use?
Most self-employed people with relatively stable income do well with the safe harbor method. It is predictable, it protects you from penalties, and it requires minimal math each quarter, (essentially none if you use the vouchers included with your prior year tax return). If your income has gone up substantially from last year, it is worth doing a rough mid-year estimate to see if you should be setting aside more than the safe harbor minimum.
If your income swings significantly quarter to quarter, the actual income method may serve you better since it keeps your payments more proportional to what you are actually earning.
When in doubt, talk to your tax preparer. This is exactly the kind of planning conversation you should be having with them every year.
What good planning looks like
Good planning does not have to be complicated. It looks like this: you know roughly what you earned each quarter, you set aside a percentage as you go, and you make your estimated payments on time. At year end, there are no surprises, just a reconciliation of what you paid versus what you owed.
Keep your books current. You can’t estimate what you owe if you do not know what you have earned. Clean, up-to-date books make estimated tax planning straightforward. Messy books make it a guessing game. If your income is variable, it helps to recalculate each quarter rather than just applying a flat percentage all year. A month where you earn significantly more than usual means your tax set-aside should go up proportionally.
A note on the QBI deduction
If you qualify for the Qualified Business Income (QBI) deduction — which allows eligible self-employed people and pass-through business owners to deduct up to 20% of qualified business income — that can meaningfully reduce your income tax bill. It does not reduce self-employment tax, but combined with the half-SE-tax deduction above, the effective tax rate on self-employment income can end up lower than the headline numbers suggest. Ask your tax preparer whether you qualify.
TL;DR
What is self-employment tax? Self-employment tax is the 15.3% tax that covers Social Security and Medicare for people who work for themselves. It replaces the FICA taxes that employees and employers normally split, so when you are self-employed, you pay both halves.
What is the self-employment tax rate? The rate is 15.3% on your net self-employment income up to the annual Social Security wage base ($184,500 for 2026). Above that threshold, only the 2.9% Medicare portion applies, with no cap.
Who has to pay self-employment tax? Anyone with net self-employment income of $400 or more in a tax year. This includes sole proprietors, single-member LLC owners, and partners in a partnership.
Can I deduct self-employment tax? You cannot deduct self-employment tax from your self-employment tax. But the IRS does allow you to deduct half of what you pay when calculating your income tax, which reduces your taxable income. It is not a dollar-for-dollar savings but it does help.
Do I have to pay estimated taxes if I am self-employed? Yes, in most cases. The IRS expects self-employed people to pay taxes as they earn throughout the year rather than settling up all at once in April. Estimated payments are due four times a year. Missing them can result in underpayment penalties even if you pay everything owed by the filing deadline.
What is the safe harbor rule for estimated taxes? The safe harbor rule lets you avoid underpayment penalties by paying at least 100% of your prior year tax liability in equal quarterly installments (110% if your adjusted gross income last year was over $150,000). You may still owe a balance at year end, but you will not be penalized for it.
How much should I set aside for self-employment taxes? A common rule of thumb is 25 to 30% of your net income if you are in a moderate income range. That is meant to cover both self-employment tax and income tax. Your actual number will depend on your total income, deductions, filing status, and state taxes.
The bottom line
Self-employment tax is not optional and it is not small, but it shouldn’t be a mystery. Once you understand what it is and build a simple system for setting money aside, it becomes just another line item you plan for instead of a bill that blindsides you.
If you want help staying on top of your numbers so tax planning is not a scramble, that is exactly what monthly bookkeeping is for. And if your books need some work before you can get there, a cleanup is a good place to start.
