When you work for someone else, certain taxes are split between you and the employer. Work for yourself and you're both parties, so you cover both portions. It catches people in their first self-employed year because it isn't withheld from anything — nobody takes it out for you.
Why the Bill Is Bigger Than Expected
The surprise isn't usually income tax. It's this: a category that was always quietly handled by a payroll department is now entirely yours, both halves of it.
Nobody sends a reminder. The first time many people learn about it is when they file.
Nothing Is Withheld
Employment means taxes leave before you ever see the money. Self-employment means every payment arrives whole and some of it isn't yours. Spending it is the single most common first-year mistake.
The habit that prevents it is moving a share out the same week money comes in, into an account you don't touch.
Estimated Payments and Your Entity
There are generally requirements to pay through the year rather than all at once, and the details depend on your situation and how your business is structured.
This is CPA work, and it's worth doing before the year closes rather than after. How you're set up can change the picture meaningfully — that's a question to ask out loud.
Want a Straight Answer for Your Own Situation?
Thirty minutes, no pitch, no obligation — just a plain look at where you stand.