The third-quarter estimated tax deadline is Sept. 15 — and payments could be more complicated for some filers amid President Donald Trump's tax changes for 2025, experts say.
Typically, you should make estimated payments for income without a tax withholding, like earnings from self-employment, freelancing or gig economy work. You may also need payments for investing profits, such as interest, dividends, capital gains or rental income.
Quarterly payments can help reduce taxes owed and "possible underpayment penalties," the IRS said in a June news release.
Electronic payments are the "most secure, fastest and easiest way to pay," according to the IRS. You can use your IRS Online Account, Direct Pay or the Electronic Federal Tax Payment System (EFTPS).
Some payments could be harder to calculate
Trump's "big beautiful bill" enacted several tax breaks that apply to 2025, and without changes to paycheck withholdings, some taxpayers could overpay through the end of the year, experts say.
For some filers, that could make quarterly estimated taxes for the third and fourth quarter of 2025 more difficult, experts say.
"I don't want them paying more taxes for Q3 and Q4 than they absolutely need to," said certified financial planner Jim Guarino, managing director at Baker Newman Noyes in Woburn, Massachusetts. He is also a certified public accountant.
The quarterly tax deadlines for 2025 are April 15, June 16, Sept. 15 and Jan. 15, 2026. However, these due dates can be easy to miss since they don't align with calendar quarters, experts say.
Quarterly tax deadlines for 2025
Jan. 1 – March 31 (1st quarter): April 15
April 1 – May 31 (2nd quarter): June 16
June 1 – Aug. 31 (3rd quarter): Sept. 15
Sept. 1 - Dec. 31 (4th quarter): Jan. 15, 2026
Estimated payments aren't 'one-size-fits-all'
You can avoid an underpayment penalty by following the safe harbor guidelines, experts say.
To follow the rule, you must pay at least 90% of your 2025 taxes or 100% of your 2024 taxes, whichever is smaller.
That threshold jumps to 110% if your 2024 adjusted gross income was $150,000 or more, which you can find on line 11 of Form 1040 from your 2024 tax return.
However, the safe harbor protects you only from underpayment penalties. If you don't pay enough, you could still owe taxes for 2025, experts say.
"There's not a one-size-fits-all" for estimated tax payments, said Melanie Lauridsen, vice president of tax policy and advocacy at the American Institute of Certified Public Accountants.
By working with a tax professional, they can run projections for 2025 to help decide the right payments for Q3 and Q4, she said.



