Mark Your Calendar: Every Important Tax Date for 2026
Missing a tax deadline can result in penalties, interest charges, and lost refund opportunities. This comprehensive guide covers every important tax date for the 2026 filing season covering the 2025 tax year.
January 2026
January 15, 2026
Q4 2025 Estimated Tax Payment Due. This is the final quarterly estimated tax payment for the 2025 tax year. Self-employed individuals, freelancers, and anyone who does not have sufficient taxes withheld should make this payment to avoid underpayment penalties. Use Form 1040-ES or pay electronically through IRS Direct Pay.
January 27, 2026 (approximate)
IRS Begins Accepting 2025 Tax Returns. Filing early has significant advantages: you receive your refund sooner, you reduce the window for identity theft, and you avoid the stress of the April deadline.
January 31, 2026
Employer W-2 and 1099-NEC Deadline. Employers must furnish W-2 forms to employees and 1099-NEC forms to independent contractors by this date.
March 2026
March 16, 2026
S-Corporation and Partnership Returns Due. Form 1120S and Form 1065 returns are due, along with Schedule K-1s to partners and shareholders.
April 2026
April 15, 2026 — THE BIG DEADLINE
This is the most important tax date of the year. Multiple obligations converge:
- Individual tax returns (Form 1040) due for the 2025 tax year
- Tax payments due — Even if you file an extension, any tax owed must be paid by this date
- IRA contribution deadline — Last day for 2025 Traditional or Roth IRA contributions
- HSA contribution deadline — Last day for 2025 HSA contributions
- Q1 2026 estimated tax payment due
- Extension filing deadline — File Form 4868 for automatic 6-month extension
Critical Reminder
An extension to file is NOT an extension to pay. If you owe taxes and file an extension without paying, you will accrue penalties (0.5% per month) and interest on the unpaid balance from April 15 forward.
June 2026
June 15, 2026
Q2 2026 Estimated Tax Payment Due. Second quarterly estimated tax payment for the 2026 tax year.
U.S. Citizens Abroad Filing Deadline. Taxpayers living outside the United States receive an automatic 2-month extension. However, interest still accrues from April 15.
September 2026
September 15, 2026
Q3 2026 Estimated Tax Payment Due. Third quarterly estimated tax payment.
Extended S-Corp and Partnership Returns Due.
October 2026
October 15, 2026
Extended Individual Returns Due. If you filed Form 4868 in April, your individual return must be filed by this date. No further extensions available.
Avoiding Penalties
- Failure to File: 5% of unpaid tax per month, up to 25% maximum
- Failure to Pay: 0.5% of unpaid tax per month, up to 25% maximum
- Underpayment of Estimated Tax: Variable rate based on federal short-term rate + 3%
The most important takeaway: always file on time, even if you cannot pay the full amount. The failure-to-file penalty is 10 times larger than the failure-to-pay penalty.
Set Up Your Reminders
Use our tax calculators now to estimate what you will owe and plan your payments accordingly.