Alaska taxpayers face 8 separate tax deadlines in 2026, and missing a quarterly one is not a slap on the wrist: the IRS charges an underpayment penalty under IRC Section 6654 at the federal short-term rate plus 3 percentage points, computed quarter by quarter.
Here is every date that matters, in the order it arrives, with weekend and holiday shifts already applied. Deadlines for every other state are in our state tax deadlines index.
1. March 16, 2026: S corporation and partnership returns are due
Form 1120-S and Form 1065 returns for tax year 2025 are due today, and every shareholder or partner is waiting on a Schedule K-1 before they can finish their personal return. If the books are not closed, file Form 7004 for an automatic extension to September 15, 2026.
Do this today: confirm your 2025 bookkeeping is closed and K-1s are on track before the deadline week.
2. April 15, 2026: Federal individual returns and 2025 balances are due
Form 1040 for tax year 2025 is due today. This is also the payment deadline: filing an extension moves your paperwork to October 15, 2026, but any tax you owe is still due now, and interest starts the day after.
Do this today: if you cannot file yet, pay your best estimate of the balance with the extension so interest never starts running.
3. April 15, 2026: Q1 estimated taxes are due for 2026
The Q1 federal estimated payment covers income earned January 1 to March 31. If you earn income without withholding, business profit, freelance work, rentals, or investment gains, the IRS wants its share now, not next April. With no Alaska income tax, only the federal payment applies.
4. The tip that replaces every date on this list
Nobody misses a quarterly payment because they cannot read a calendar. They miss it because the amount is a mystery: guessing what you owe feels bad enough to postpone. Amadae calculates your federal quarterly estimates from your actual income as the year happens, then reminds you before every date on this page with the number already filled in.
That turns 8 deadlines into 8 confirmations.
5. June 15, 2026: Q2 estimated taxes are due for 2026
The Q2 federal estimated payment covers income earned April 1 to May 31. If you earn income without withholding, business profit, freelance work, rentals, or investment gains, the IRS wants its share now, not next April. With no Alaska income tax, only the federal payment applies.
An extension moves your paperwork to October. It does not move your money. The IRS wants payment in April either way.
6. September 15, 2026: Q3 estimated taxes are due for 2026
The Q3 federal estimated payment covers income earned June 1 to August 31. If you earn income without withholding, business profit, freelance work, rentals, or investment gains, the IRS wants its share now, not next April. With no Alaska income tax, only the federal payment applies.
7. September 15, 2026: Extended S corporation and partnership returns are due
If you filed Form 7004 in the spring, this is the real deadline for the 2025 1120-S or 1065. There is no second extension, and late pass-through returns are penalized per owner, per month.
8. October 15, 2026: Extended individual returns are due
The final stop for 2025 Form 1040 filings on extension. Remember that the payment was due back in April 15, 2026: October is a filing deadline, not a paying deadline.
9. January 15, 2027: Q4 estimated taxes are due for 2026
The Q4 federal estimated payment covers income earned September 1 to December 31. If you earn income without withholding, business profit, freelance work, rentals, or investment gains, the IRS wants its share now, not next April. With no Alaska income tax, only the federal payment applies.
10. Where to pay your federal taxes online
Federal balances and estimated payments are made at irs.gov/payments using IRS Direct Pay (no fee from a bank account) or EFTPS.
Alaska has no state income tax, so there is no state portal to keep track of. Every payment on this list is federal.
11. Stop memorizing dates
The list above is everything 2026 will throw at you: 8 deadlines, four of them quarterly estimates that most people underpay. You can calendar all of them, or you can have a tax team that computes the amounts from your real income and never lets a date pass quietly.
Book your free review and walk out knowing exactly what you should be paying this quarter. Deadlines for every other state are in our state tax deadlines index.