What is Self-Employment Tax?

You quit the 9-to-5. You're doing your own thing. Life is good.

Then tax season arrives and hits you with a bill you weren't expecting and it's not just income tax. There's another tax sitting on top of it, and most new freelancers don't find out about it until it's too late.

It's called self-employment tax.

Here's the thing most people get wrong: self-employment (SE) tax is not the same as income tax. They're two completely separate bills on the same money.

When you work a regular job, your payslip shows a deduction for Social Security and Medicare. That's 7.65% coming out of your pay. What most people don't realise is that your employer is also quietly paying another 7.65% on your behalf. You never see it, but it's being paid.

When you work for yourself? You're the worker and the employer. So you pay both halves. That's where the 15.3% comes from.

It's not a penalty for being self-employed. It's the same tax everyone pays, it just used to be invisible to you.

SE tax is made up of two parts:

• Social Security tax: 12.4% — this applies to your net earnings up to $184,500 (that's the 2026 cap)

• Medicare tax: 2.9% — this applies to all your net earnings, no cap, no ceiling

So if you earn above $184,500, the Social Security portion stops but Medicare keeps going forever.

Not quite and this is where it gets a little more forgiving.

The IRS doesn't make you pay 15.3% on every dollar you earn. First, you multiply your net profit by 92.35%. That's the number your SE tax is based on.

Why? Because when an employee pays FICA, they're not paying tax on the employer's contribution, that part is a business cost. The 92.35% rule gives you the same treatment. It strips out the "employer half" so you're not being taxed more harshly than someone doing the same work on a payroll.

Here's a simple example:

• You made $50,000 freelancing this year

• $50,000 × 92.35% = $46,175 (your taxable SE earnings)

• $46,175 × 15.3% = ~$7,065 in SE tax

That $7,065 is on top of whatever income tax you owe. Yes, it stings. But now you know to expect it.

You owe SE tax if your net self-employment earnings are $400 or more for the year. That's the threshold and it doesn't matter if that $400 came from one client or ten. It all adds up together.

One thing that surprises people: it doesn't matter how old you are, and it doesn't matter if you're already receiving Social Security. If you're making a profit from self-employment, you owe SE tax on it.

Here's something that actually works in your favour.

You can deduct half of your SE tax from your income before calculating what you owe in income tax. It's called an above-the-line deduction, which means you get it automatically.

You don't need to itemise.

Using the example above: half of $7,065 is about $3,532. That amount comes off your income, which shrinks your income tax bill.

Important: it doesn't reduce the SE tax itself, you still pay the full 15.3%. But it does lower the income tax you owe, which helps.

There's no employer taking tax out of your pay throughout the year. So the IRS expects you to do it yourself, four times a year, through what's called estimated tax payments.

The 2026 due dates are:

• Q1: 15 April 2026

• Q2: 15 June 2026

• Q3: 15 September 2026

• Q4: 15 January 2027

The most common (and most avoidable) self-employment tax mistake? New freelancers don't pay quarterly, then get hit with a massive lump sum in April plus a penalty for not paying throughout the year. That penalty is basically interest on the tax you should have been paying all along.

The fix is simple: know your profit, estimate what you'll owe, and pay it four times a year instead of all at once.

SE tax is calculated on your profit, not your revenue. That means every legitimate business expense you track lowers your profit, which lowers your SE tax.

Miss a deduction? That money gets taxed at 15.3% on top of your income tax rate. Catch it? You keep it.

There's another thing worth knowing: from 2026, the threshold for 1099 forms jumped from $600 to $2,000. That means fewer reminder forms are landing in your inbox and more of your income is going unreported by whoever paid you. The only person keeping track of what you actually earned is you.

That's why real-time bookkeeping isn't just tidy admin. It's how you figure out what your quarterly payment should be, and how you make sure you're not handing over more than you need to.

Self-employment tax is 15.3%, Social Security and Medicare, on top of your regular income tax. You've always paid it; you just used to have an employer hiding half of it from you.

Now that you're your own boss, it's yours to manage. And the good news is, once you understand how it works, it's completely manageable.

Track your income. Track your expenses. Pay quarterly. And you'll never be blindsided by a tax bill again.