Quarterly Estimated Taxes 2025 — Don’t Miss Your Q3 Deadline
If you’re self-employed, a contractor, or run a small business, September isn’t just back-to-school season—it’s also tax season in disguise.
The IRS expects you to pay as you go. That means Quarterly Estimated Taxes—and for Q3 of 2025, your payment is due September 15, 2025. Miss it, and you could face unnecessary penalties that eat into your hard-earned income.
Here’s what you need to know about who owes, how to calculate, and how to plan smarter for the rest of the year.
Q3 2025 Deadline at a Glance
Payment Due: Monday, September 15, 2025
Covers Income: Earnings from June 1 – August 31, 2025
Who Must Pay:
Freelancers / contractors (1099 workers)
Self-employed individuals
Small business owners without sufficient tax withholding
Landlords or investors with significant untaxed income
How to Know if You Owe Estimated Taxes
You generally must make estimated payments if you expect to owe $1,000 or more in tax for the year (after withholding and credits).
Quick check:
W-2 employees usually don’t pay because their employer withholds.
1099 contractors, gig workers, and small business owners almost always do.
How to Calculate Q3 Estimated Taxes
The IRS requires you to pay the smaller of:
90% of your expected 2025 tax liability, OR
100% of your 2024 total tax liability (110% if AGI was over $150,000).
Pro Tip: Use your Profit & Loss (P&L) or bank statements from June–August to update income, then apply deductions (mileage, home office, business expenses) before estimating.
Penalties for Missing Q3 Payment
Miss the September 15 deadline, and the IRS charges:
Failure-to-pay penalty: 0.5% of unpaid tax per month, plus
Interest: Adjusted quarterly (~8% in 2025).
Even if you file your return on time, late estimated payments mean extra costs.
Smart Planning Tips for Q3 & Beyond
Automate payments using IRS Direct Pay or EFTPS to never miss a deadline.
Sync with bookkeeping: Use your P&L each quarter to refine estimates.
Leverage deductions now: Vehicle mileage, retirement contributions, and Section 179 equipment purchases can shrink your quarterly payment.
Set aside 25–30% of income from each payment you receive so cash flow stays healthy.
Plan ahead for Q4: Your final payment for 2025 is due January 15, 2026.
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1. When is the Q3 2025 estimated tax deadline?
September 15, 2025.2. What period of income does Q3 cover?
June 1 – August 31, 2025.3. How do I pay estimated taxes?
Use IRS Direct Pay, EFTPS, or mail Form 1040-ES with a check or money order.4. What happens if I miss the deadline?
Penalties + interest apply until paid. Even if you catch up later, late payments cost extra.5. Can I skip Q3 if I overpaid in earlier quarters?
Yes—if you’ve already met your required safe harbor (90% of 2025 or 100% of 2024 tax liability).
Paying quarterly taxes might feel like a chore, but staying ahead means no penalties and smoother cash flow. Q3’s deadline is right around the corner—don’t leave it to chance.
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