6 Tax Deadlines for October 15 You Don't Want to Miss
Everything you need to know about the IRS Oct. 15 federal tax extension deadline and other key October tax deadlines.
The October 15 federal tax extension deadline is coming up, but did you know several other tax deadlines fall on the same day?
From excess IRA rules and solo 401(k) contributions to special exceptions for those living in federally declared disaster zones, the October 15th due date could significantly affect your 2026 return.
For example, missing one of these deadlines can result in losing valuable deductions or credits, and in some cases, incurring IRS penalties.
Below, we outline six key tax deadlines on October 15 that every filer should be aware of, along with who qualifies for extra time. Let’s dive in.
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1. October tax extension deadline
Last year's federal tax returns were originally due on April 15, 2026. But if you were granted a tax extension by the IRS, you need to file by Oct. 15, 2026.
Failure to file could result in a penalty of 5% of taxes due for every month (or partial month) that your return is late.
And yes, the IRS can charge interest on penalties, making that amount even higher.
However, the failure-to-file penalty is separate from late payment penalties. This means that your payment for 2025 federal tax returns was due on April 15, 2026, regardless of whether you were granted a federal tax extension for a later date.
So, if you haven't paid your taxes yet, you should do so as soon as possible. The IRS offers several options for paying taxes, even if you can't pay the full amount.
Can you avoid a late filing penalty? The IRS won’t impose a failure-to-file penalty if you had no tax liability last year or are due a tax refund. Also, if you lived or had records in a federally declared disaster area, you may have more time to file taxes in your state.
2. IRS tax deadline for disaster areas
Earlier this year, severe storms devastated parts of Wisconsin and Michigan. As a result, the IRS granted affected individuals an extension of their original April 15 federal tax filing deadline and moved certain contributions and tax payments to later due dates.
- The deadline for 2025 individual federal income tax returns is postponed to November 2, 2026.
- Quarterly payroll and excise tax returns originally due on April 30 and July 31, 2026.
More tax payments may be postponed for individuals in qualifying parts of these states. For more information, see the IRS disaster relief webpage.
Taxpayers in other states affected by disasters may have until February 1, 2027, to meet the federal tax filing deadline. This can happen if you have already filed for an October 15 deadline extension and were impacted by a federally declared disaster in Hawaii, Indiana, Louisiana, Michigan, Mississippi, Nebraska, Washington, or West Virginia.
But not all taxpayers may qualify for the automatic tax deadline extensions. You can check the IRS's disaster relief page for more information.
Note: Affected taxpayers may be able to take a special disaster distribution from their retirement plan or IRA without incurring the 10% early distribution tax. But be sure to check your plan’s specific rules and guidance.
3. State tax deadlines
Most state tax extension deadlines are also due Oct. 15. Some states, such as Alabama and Kansas, grant automatic tax extensions if you request a federal filing extension.
However, not all states do, and the tax extension deadlines for some states can fall after Oct. 15. For example, the extended tax deadline for Virginia is Nov. 1, and Louisiana state personal income tax returns aren't due until Nov. 15.
Exceptions may apply to deadlines that fall after Oct. 15. For example, some states won't grant a filing extension if you owe tax. So, it's important to check with your state’s Department of Revenue before waiting to file your state tax return.
4. SEP IRA contribution deadline: Sole proprietors and C-corps
If you filed for a federal tax extension, Oct. 15 is the deadline to contribute to your employees' 2025 SEP IRA accounts if you are a sole proprietorship or C-corporation. The contribution deadline for this type of IRA aligns with your federal income tax return deadline, which includes any granted extensions.
Making contributions to this type of IRA could lower your tax liability since you can claim them as a tax deduction on your return; however, it's important to keep in mind that the IRS only allows you to deduct up to 25% of employee compensation (or the amount of your contributions, whichever is lower).
Note: The extended deadline to contribute to a SEP IRA for your employees was September 15, 2026, if you are an S corporation or partnership entity.
5. Solo 401(k) contribution deadline
Self-employed sole proprietors and C corporations who requested a valid federal tax filing extension have until October 15, 2026, to contribute to a Solo 401(k).
Rather than a strict 25% cap on your entire contribution, your maximum limit is calculated by combining your employee and employer parts up to 100% of your net earned self-employment income, maxing out at the following caps:
- Under Age 50: Up to $70,000 (consisting of up to $23,500 as an employee elective deferral, plus up to 25% of net adjusted self-employment income as an employer profit-sharing contribution).
- Ages 50 to 59: Up to $77,500 (includes a standard $7,500 catch-up contribution).
- Ages 60 to 63: Up to $81,250 (includes an enhanced SECURE 2.0 catch-up contribution of $11,250).
- Age 64 and Older: Up to $77,500 (reverts back to the standard $7,500 catch-up contribution).
6. Correct excess IRA contributions
If you accidentally made excess IRA contributions ("ineligible contributions") last year and were granted a federal tax extension, act quickly!
Since the IRS will tax you 6% on the excess in your account, you’ll want to have withdrawn the excess funds before the Oct. 15 deadline.
Here are the contribution limits for traditional IRAs and Roth IRAs:
- For taxpayers under 50 years old, $7,000 or your taxable compensation for 2025, whichever is less.
- For taxpayers 50 years old or older, $8,000 or your taxable compensation for 2025, whichever is less.
October 15 tax deadline time
You have until October 15 to meet the above deadlines unless you were affected by a federal disaster area. In disaster-affected areas, taxpayers typically have later dates to file their federal returns (see individual IRS notices for more information).
Taxes for all other taxpayers who filed an extension or are otherwise subject to the Oct. 15 deadline are due by midnight. This means you’ll want your return filed by 11:59 that night.
However, any documents you send via regular mail must be postmarked by Oct. 15.
Whether you mail your documents or submit them electronically, it's not possible to predict exactly how long it will take to complete all your forms, so it’s best to start ahead of time.
Read More
- States With IRS Tax Deadline Extensions This Year
- How to Pay the IRS if You Owe Taxes
- When Are Estimated Tax Payments Due in 2026?
- What Happens if You Missed the Tax Deadline?
