If you earned money last year from a side hustle, a gig app, a rental, or a client who paid you directly, the IRS expects a piece of it four times a year — not once in April.
The next estimated tax deadline is September 15, and it catches a lot of otherwise careful people off guard.
When you work a regular job, your employer quietly withholds taxes from every paycheck.
Nobody hands you that job when you're self-employed.
You are the withholding department now, and the IRS doesn't send reminders with a friendly tone.
Miss the payments and you can owe a penalty, even if you get a refund later.
The penalty isn't dramatic, but it's real.
The IRS charges interest on underpayments, and the rate has been running around 7% to 8% in recent quarters — higher than what most savings accounts pay.
That's money leaving your pocket for no reason other than timing.
Generally, if you expect to owe at least $1,000 in taxes for the year after subtracting withholdings and credits, you're in the club.
That includes freelancers, independent contractors, small business owners, people with investment income, and anyone whose side gig has grown past a hobby.
The rule of thumb is to send roughly 25% of your net self-employment income each quarter, though the exact number depends on your bracket and deductions.
A simpler safety net: aim to pay at least 90% of this year's tax bill or 100% of last year's, whichever is smaller.
Meet that and the penalty generally goes away.
If your income is uneven — a huge spring, a quiet summer — you can use the annualized installment method to pay less in the lean quarters.
It takes more paperwork, but it can keep cash in your account when you need it.
Also, check whether your day job's withholding can cover the gap.
You can ask your employer to withhold extra from each paycheck by filing a new W-4.
That's often easier than remembering four separate deadlines, and the IRS treats withholding as paid evenly throughout the year — even if you cram it into December.
Most states with income tax run their own quarterly system, sometimes on different dates.
California, for instance, doesn't always line up with the federal calendar.
If you've already missed a payment this year, don't panic and don't wait until April.
Send what you can now through IRS Direct Pay or your IRS online account.
The penalty is calculated on how long the money is late, so paying sooner stops the bleeding.
One more thing: the IRS never demands immediate payment by gift card, wire transfer, or crypto, and it doesn't open with a threatening phone call.
Scammers ramp up around every deadline, so verify anything suspicious directly at IRS.gov.
Set a calendar reminder for September 15, January 15, and April 15.
Your future self, staring at a tax bill you've already covered, will thank you.
The bottom line: quarterly taxes feel like a hassle, but they're really just forced budgeting.
Final Thoughts
Treat each payment as a bill you owe yourself, and April stops being a financial ambush.