The last day to file state taxes in most states is April 15, 2026, the same day federal returns are due. Five states set later statutory deadlines, nine states have no personal income tax at all, and anyone who files a valid extension generally has until October 15, 2026 to send in the paperwork. Payment, however, is still due on the original April date.
The April 15 Default
Most states that levy a personal income tax deliberately align their filing deadline with the federal date so residents can handle both returns together.1Internal Revenue Service. When to File When April 15 lands on a Saturday, Sunday, or legal holiday, the deadline shifts to the next business day. In 2026, April 15 is a Wednesday, so there is no automatic shift. The date stands.
States With Later Deadlines
Five states have written later filing dates into their tax codes. These are fixed statutory deadlines that apply every year, not just when a weekend or holiday interferes:
- Hawaii: April 20
- Delaware: April 30
- Iowa: April 30
- Virginia: May 1
- Louisiana: May 15
If you live in one of these states, the federal return will be finished before the state one is even due.
Holiday Shifts
Regional holidays can nudge the effective deadline back by a day or two even in states that normally follow April 15. Patriot’s Day in Maine and Massachusetts, observed on the third Monday of April, and Emancipation Day in Washington, D.C., on April 16, can push filing dates when they fall next to the standard deadline.2Internal Revenue Service. Patriots Day Gives Some Taxpayers an Extra Day to File and Pay Taxes The IRS announces adjusted dates in advance in years when this happens, and the extra time usually extends to state returns for affected residents.
Disaster Postponements
A federal or state disaster declaration in your area usually postpones filing and payment deadlines automatically. You don’t have to submit a form or call anyone. The IRS identifies taxpayers in covered zones and extends their deadlines, sometimes by several months.3USAGov. Tax Relief for Federally Declared Disaster Areas Most states with an income tax follow suit, though the length of relief varies. If a disaster has hit your area, check both the IRS disaster relief page and your state revenue department for the specific dates.4Internal Revenue Service. IRS Announces Tax Relief for Taxpayers Impacted by Severe Storms in Washington
States With No Income Tax
Nine states do not levy a personal income tax: Alaska, Florida, Nevada, New Hampshire, South Dakota, Tennessee, Texas, Washington, and Wyoming. If you live in one of these states and earn no income from a state that does tax it, there is no state return to file and no deadline to track. New Hampshire was the last to join the group, ending its tax on interest and dividends starting in 2025.
Earning income in a taxing state can still create a filing obligation there. A Texas resident working remotely for a New York employer, for example, may need to file a New York nonresident return even though Texas itself asks for nothing.
Getting an Extension
If you can’t finish the return by the original deadline, you can request an extension. About half the states grant a state extension automatically once you file federal Form 4868 with the IRS. You attach a copy of the federal form, or note the federal extension on your state return, when you eventually file. California, Colorado, Illinois, Iowa, Kentucky, and Virginia are among the states that work this way.
Other states want their own extension form, typically called an Application for Extension of Time to File. You’ll need your Social Security number or ITIN, an estimate of your total state tax liability for the year, and the amount you’ve already paid through withholding or estimated payments. Significantly underestimating what you owe can invalidate the extension and expose you to late-filing penalties, so the estimate matters.
A federal extension gives you six additional months, moving the paperwork deadline to October 15, 2026.5Internal Revenue Service. Form 4868 – Application for Automatic Extension of Time to File US Individual Income Tax Return Most states mirror this and set their extended deadline on the same date. States with later original deadlines sometimes have correspondingly later extensions; Hawaii, for example, extends to October 20.
The extension is automatic in the sense that it’s granted as long as you request it properly and on time. You don’t have to explain the delay. But automatic doesn’t mean optional. If you simply don’t file and don’t request, you’re treated as late from day one.
Payment Is Still Due in April
Here’s the most expensive misunderstanding in tax season: an extension to file is not an extension to pay.6Internal Revenue Service. IRS Reminds Taxpayers an Extension to File Is Not an Extension to Pay Taxes Even with a valid extension moving your paperwork to October, any tax you owe is still due by the original April date. If you’re expecting a refund, the extension carries no penalty risk. But if you owe money and don’t pay by April, interest and penalties start running immediately.
When you’re unsure of the exact amount, the safest move is to estimate and overpay. Any overpayment comes back as a refund once the completed return is filed.
What Late Costs
The penalty for not filing is far steeper than the penalty for not paying, and people often get this backward. At the federal level, which many states mirror closely:
- Failure to file: 5% of the unpaid tax for each month or partial month the return is late, capped at 25%.7Internal Revenue Service. Failure to File Penalty
- Failure to pay: 0.5% of the unpaid tax for each month or partial month, also capped at 25%.8Internal Revenue Service. Failure to Pay Penalty
That’s a tenfold difference in the monthly rate. Filing an extension eliminates the 5% failure-to-file penalty entirely, even if you can’t pay the full balance. You’ll still owe the 0.5% failure-to-pay penalty and interest on the unpaid amount, but that’s much cheaper than both penalties stacking. When both apply in the same month, the failure-to-file penalty is reduced by the failure-to-pay amount, though the combined cost still dwarfs what a timely extension would have cost.7Internal Revenue Service. Failure to File Penalty
Interest compounds on top of the penalties. The IRS sets its underpayment rate quarterly, running at 7% annually for early 2026 and dropping to 6% for the second quarter.9Internal Revenue Service. Quarterly Interest Rates State rates on unpaid balances typically run from about 5% to 12% annually. Even if you can only pay part of what you owe, filing the extension and paying as much as possible by the original deadline is worth it.
Don’t Lose a Refund by Waiting Too Long
If the state owes you money instead, there’s no penalty for filing late. There is, however, a hard cutoff. Federal law gives you three years from the original filing deadline to claim a refund. Miss it and the money is gone, no matter how valid the overpayment.10Office of the Law Revision Counsel. 26 US Code 6511 – Limitations on Credit or Refund Most states apply a similar three-year window, with a few allowing slightly more or less time.
This trap catches people who didn’t think they needed to file at all: low earners, students, and anyone who moved between states mid-year. If tax was withheld from your paychecks in a state where you worked, that money sits with the state until you file a return to reclaim it. After three years it’s forfeit. Filing a simple return to recover withheld taxes is worth the half hour it takes.