If you made money this year without an employer withholding taxes for you, there's a bill with your name on it.
And the deadline is closer than most people think.
The next estimated tax payment for the 2025 tax year lands on **September 15**.
That covers income you earned from June through August, and it's the third of four installments the IRS expects from freelancers, gig workers, independent contractors, and anyone with significant side income.
Miss it, and the penalty isn't dramatic in any single quarter — but it compounds quietly, and by April it's real money.
Here's the part that trips people up: the IRS doesn't send a reminder.
There's no form in the mail, no email nudge.
If you owe, it's on you to know the date and pay.
Roughly a third of Americans who owe estimated taxes get hit with an underpayment penalty each year, and most of them never saw it coming because their income looked fine on paper.
You pay tax on income as you earn it, not once a year.
Employees get this handled automatically through payroll withholding.
Everyone else — 1099 workers, landlords, people earning dividends and capital gains, even some retirees — has to estimate what they'll owe and send it in four times a year: April, June, September, and January.
If you're not sure whether you qualify, there's a safe harbor worth knowing.
You generally avoid penalties if you pay at least 90% of this year's tax bill or 100% of last year's (110% if your income topped $150,000).
Hitting last year's number is often the easier target, especially in a year where income is unpredictable.
A lot of people skip September entirely and tell themselves they'll square up in April.
The penalty rate tracks the federal short-term rate plus three percentage points, and it's been elevated compared to the near-zero years of the last decade.
On a $10,000 shortfall, that's a few hundred dollars in avoidable interest — money that could've gone toward the actual tax.
The fix is less painful than the dread suggests.
Log into IRS Direct Pay or your IRS online account and make a payment in a few minutes.
You can pay by bank transfer, debit card, or credit card (cards carry a processing fee, so bank transfer usually wins).
If cash is tight, the IRS offers payment plans, though interest keeps running.
One more thing people overlook: state taxes.
Most states with income tax run their own estimated payment schedule, often on the same dates but not always.
California, for instance, has its own quirks.
Check your state's revenue department before you assume one payment covers everything.
If you're self-employed and this all feels like a lot, the single best move is to set aside a fixed percentage of every payment you receive — 25% to 30% is a common starting point — into a separate account.
Then the quarterly bill becomes a transfer, not a scramble. **Our take:** The estimated tax system isn't designed to be friendly to freelancers, and the September deadline sneaks up on people every single year.
But the penalty is one of the few financial hits in life that's almost entirely preventable with ten minutes and a login.
Final Thoughts
Pay something, even if it's not perfect — the IRS would rather have a partial payment now than nothing.