If you're self-employed, the calendar doesn't care that tax season feels months away.
The next estimated tax payment deadline is September 15, and it covers income you earned from June through August.
Miss it, and the IRS can tack on interest and a penalty that quietly eats into money you already spent.
The rule of thumb is simple: if you expect to owe at least $1,000 when you file, you're generally supposed to pay in quarterly installments.
That catches freelancers, gig workers, rideshare drivers, consultants, and plenty of retirees with investment income.
Employees usually avoid this because taxes come out of every paycheck.
Nobody withholds anything for the person selling candles on Etsy.
The IRS doesn't just want its money eventually.
Underpayment penalties work like interest on a loan you never agreed to, and they're calculated based on how long the money was missing.
Pay nothing all year, then write one big check in April, and you've effectively borrowed from the government at a rate you didn't negotiate.
The fast way to estimate: take last year's total tax, divide by four, and make sure you've paid at least that much in combined withholding and estimated payments.
That safe harbor generally protects you from penalties if your income grew.
If you earned roughly the same as last year, you can also aim for 90% of this year's actual tax bill.
Where people get tripped up is the math itself.
Your estimated payment needs to cover income tax plus self-employment tax, which runs 15.3% on net earnings up to the Social Security wage base.
That surprise is why so many first-year freelancers owe thousands in April and assume something went wrong.
They just never saw the full bill coming.
A few practical moves before September 15.
Set aside 25% to 30% of every payment you receive into a separate account so the money is there when the deadline lands.
Use IRS Direct Pay or your IRS online account to send money free, and schedule it a day or two early so it doesn't post late.
If you have a retirement account like a SEP IRA, contributions can lower your taxable income, but you have to actually make them before the deadline that applies.
If you've already fallen behind, you have options.
You can request a payment plan through the IRS, and the short-term version costs less than most people assume.
You can also increase withholding from a W-2 job to cover a freelance shortfall, since withholding is treated as paid evenly throughout the year even if you ramp it up in December.
That trick alone rescues a lot of people.
One more thing worth checking: state estimated taxes.
Most states with income tax run their own quarterly system, often with the same mid-September deadline.
Paying the feds and forgetting your state is a two-penalty mistake.
The honest takeaway is that estimated taxes aren't a punishment aimed at freelancers.
They're just the version of withholding that nobody sets up for you.
Automate the transfer, mark the four dates on your calendar, and the whole thing stops being a yearly scare. **Opinion:** The people who get burned by estimated taxes usually aren't bad with money.
They're just missing one calendar reminder.
Final Thoughts
Setting aside a percentage of each payment now costs you nothing and saves you a penalty later, which is about as close to free money as the tax code gets.