The 2026 Strategic Tax Calendar
The IRS doesn't forgive forgetting. Missing a deadline can trigger penalties of up to 25% of your unpaid tax. We track these dates so you can focus on running your life.
January 15, 2026
Q4 2025 Final Payment. The final chance to pay enough tax to avoid the "Underpayment Penalty" for the 2025 tax year.
Strategist Note
"We aim for the 'Safe Harbor' threshold—paying 100% of last year's tax (110% for high earners) to immune you from penalties."
January 31, 2026
W-2 & 1099-NEC Deadline. You must mail W-2s to employees and 1099s to contractors. This is also the deadline to file these with the Social Security Administration and IRS.
March 16, 2026
S-Corp (1120-S) & Partnership (1065) Filing. These returns must be filed early because they generate the K-1 forms you need for your personal return.
Automatic Extension
"If your books aren't ready, we file Form 7004 today to give you 6 more months. No questions asked."
April 15, 2026
Individual (1040) & C-Corp (1120) Deadline.
- Last day to contribute to IRA/HSA for 2025.
- Q1 2026 Estimated Tax Payment Due.
- Deadline to file FBAR for foreign accounts.
June 15, 2026
US Citizens Abroad. Automatic 2-month extension for expats. Also the due date for Q2 Estimated Payments.
Check Your Withholding
"Mid-year checkup: Did you sell stock? Get a bonus? Adjust payments now to avoid a surprise next April."
September 15, 2026
Final Deadline for S-Corps & Partnerships. If you filed an extension in March, this is the end of the road. Q3 Estimates are also due.
October 15, 2026
Final 1040 Deadline. The extension period ends today. If you miss this, you are officially late and penalties maximize.
System Shutdown
"The IRS shuts down e-filing for maintenance shortly after this date. Don't get stuck mailing paper returns."
The Cost of Procrastination
The IRS penalizes inaction more than mistakes. Here is exactly what it costs to ignore the calendar.
Failure to File
The most expensive penalty. The IRS charges 5% of your unpaid taxes for every month your return is late, capping at 25%.
Failure to Pay
Less severe, but steady. Charged at 0.5% per month. NOTE: If you file on time but can't pay, you avoid the 5% penalty above. Always file!
Already Missed a Deadline?
Don't panic. We specialize in penalty abatement. We can often get penalties removed if you have a valid reason.
Fix My Tax Issues