If you made money this year without an employer withholding taxes for you, the IRS is expecting a payment — and the next deadline is closer than most people think.
The third-quarter estimated tax payment for 2025 is due September 15, and it lands on a date many gig workers, freelancers, and small business owners have never circled on a calendar.
When you work a traditional job, taxes vanish from each paycheck before you ever see the money.
When you drive for a rideshare app, sell crafts online, or pick up contract work, that money arrives whole.
It isn't — it's a loan you'll have to repay with interest if you don't send the government its cut four times a year.
The IRS generally wants estimated payments if you expect to owe at least $1,000 for the year.
That threshold catches far more people than most realize.
A single side hustle that nets a few thousand dollars can push you over it, and the penalty for underpaying isn't a one-time slap.
It's calculated as interest that accrues daily, so waiting until April to settle up quietly costs more the longer you delay.
The math scares people off, but it's simpler than it looks.
Employees split Social Security and Medicare taxes with their boss.
Self-employed workers pay both halves — the full 15.3% self-employment tax — plus regular income tax on top.
A rough rule many accountants suggest is setting aside 25% to 30% of every payment you receive for contract work.
On a $2,000 project, that's $500 to $600 that was never really yours.
You can usually avoid a penalty by paying in at least 90% of this year's tax bill or 100% of last year's, whichever is smaller.
If your income jumped this year, basing payments on last year's return — often called the safe harbor — can keep you out of trouble even if you ultimately owe more in April.
The people who get burned most are often the ones with the steadiest income.
A freelancer who lands one big client in March, spends the money, and forgets about it until tax season is a classic penalty case.
So is a retiree pulling from a side consulting gig, or a parent selling items online who never thought of themselves as "self-employed." If you've missed earlier deadlines this year, you're not stuck.
You can catch up by sending a larger payment now, and the IRS also offers an online account where you can schedule payments directly from a bank account.
Paying through the IRS site is free; third-party processors tack on fees.
Some people also ask their employer to withhold extra from a W-2 job to cover side-income taxes, which spreads the burden without extra paperwork.
One more thing worth checking: state taxes.
Most states with income tax run their own estimated payment schedules, and a few deadlines don't line up with the federal ones.
Missing the state version creates a second penalty stack that's easy to overlook.
The bigger point is that estimated taxes aren't a punishment aimed at gig workers.
They're just the flip side of getting paid without withholding.
The system assumes you'll handle it yourself — and it charges you when you don't.
If you're unsure how much to send, a single session with a tax professional often costs less than the penalty you'd rack up guessing.
Final Thoughts
Treating that set-aside money as untouchable is the difference between a manageable tax bill and a nasty spring surprise.