Q4 Tax Deadline — January 15, 2027
Your final quarterly estimated tax payment is due January 15. This is your last chance to get your estimated payments right before filing season. Here's what to know — including year-end tax moves you can still make.
Who Needs to Pay Q4 Estimated Taxes
Q4 covers income earned September through December — four months of income, the longest quarter. Even if you've already paid Q1-Q3, don't skip Q4. Each quarter's penalty runs independently.
If you haven't made any quarterly payments all year and you owe more than $1,000, you'll face penalties on all four quarters. Paying Q4 on time at least stops the bleeding for the final quarter.
Year-End Tax Planning — Last Chance Before December 31
Q4 is unique because you can still make moves that reduce your tax bill before the year closes. A SEP-IRA lets self-employed individuals contribute up to 25% of net self-employment income (max $72,000 for 2026). Equipment, software, and tools purchased by December 31 can be deducted this tax year under Section 179.
By Q4, you have 9+ months of real income data. If your annual income is significantly different from your original estimate, recalculate now.
How to Pay — IRS Direct Pay
Pay via IRS Direct Pay at irs.gov/directpay — free, secure, no account required. Important: Q4 payments for tax year 2026 are due January 15, 2027. When selecting the tax period, ensure you're selecting the correct year (2026, not 2027).
What if I Miss the January 15 Deadline?
The Q4 penalty runs from January 15 to April 15 — only 3 months, the shortest penalty period. At approximately 8% annually, missing Q4 costs roughly 2% of the underpaid amount.
Special exception: if you file your annual return and pay your full balance by January 31, the IRS waives the Q4 penalty entirely. This only applies to Q4.
All 2026 Quarterly Deadlines
Frequently Asked Questions
Can I skip Q4 if I'm going to file my return early?
Yes — if you file your return and pay your full balance by January 31, the IRS waives the Q4 underpayment penalty. This is a special exception for Q4 only.
Is it too late to make retirement contributions for the tax year?
For a SEP-IRA, you have until your tax filing deadline (including extensions) to contribute. For a Solo 401(k), employee contributions must be made by December 31, but employer contributions can be made until the filing deadline.
My income was much lower this year. Will I get a refund on overpaid quarterly taxes?
Yes. If your total quarterly payments exceed your actual tax obligation, the excess is refunded when you file your annual return.
What's the safe harbor rule?
If your total estimated payments for the year equal at least 100% of last year's tax liability, you won't owe a penalty. Threshold is 110% if AGI exceeded $150,000.
Missed a previous quarter? Here's what to do →
Qalm provides estimates for planning purposes. This is not tax advice. Consult a qualified tax professional for your specific situation.