Wyoming taxpayers face 8 separate tax deadlines in 2027, 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. Wyoming has no state income tax, so only the federal dates below apply.
1. March 15, 2027: S corporation and partnership returns are due
Form 1120-S and Form 1065 returns for tax year 2026 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, 2027.
Do this today: confirm your 2026 bookkeeping is closed and K-1s are on track before the deadline week.
2. April 15, 2027: Federal individual returns and 2026 balances are due
Form 1040 for tax year 2026 is due today. This is also the payment deadline: filing an extension moves your paperwork to October 15, 2027, 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, 2027: Q1 estimated taxes are due for 2027
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 Wyoming income tax, only the federal payment applies. Paying inside the safe harbor, 100% of last year's tax (110% for higher incomes) or 90% of this year's, keeps the underpayment penalty off the table.
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, 2027: Q2 estimated taxes are due for 2027
The Q2 federal estimated payment covers income earned April 1 to May 31. With no Wyoming income tax, only the federal payment applies.
A bigger payment in Q4 does not undo the penalty that started accruing back in Q1.
6. September 15, 2027: Q3 estimated taxes are due for 2027
The Q3 federal estimated payment covers income earned June 1 to August 31. With no Wyoming income tax, only the federal payment applies.
7. September 15, 2027: Extended S corporation and partnership returns are due
If you filed Form 7004 in the spring, this is the real deadline for the 2026 1120-S or 1065. There is no second extension, and late pass-through returns are penalized per owner, per month.
8. October 15, 2027: Extended individual returns are due
The final stop for 2026 Form 1040 filings on extension. Remember that the payment was due back in April 15, 2027: October is a filing deadline, not a paying deadline.
9. January 18, 2028: Q4 estimated taxes are due for 2027
The Q4 federal estimated payment covers income earned September 1 to December 31. With no Wyoming income tax, only the federal payment applies. The nominal 15th lands on a weekend or holiday this quarter, so the deadline shifts to the next business day, which is the date above.
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.
Wyoming has no state income tax, so there is no state portal to keep track of. Every payment on this list is federal.
11. Tax deadlines in states bordering Wyoming
If you moved during the year, work across a state line, or file in more than one state, each state keeps its own filing calendar:
- Colorado tax deadlines for 2027
- Idaho tax deadlines for 2027
- Montana tax deadlines for 2027
- Nebraska tax deadlines for 2027
- South Dakota tax deadlines for 2027 (no state income tax)
- Utah tax deadlines for 2027
Looking back? See the Wyoming tax deadlines for 2026.
12. Stop memorizing dates
Set a reminder for the next date on this list before you close the tab, or have a tax team compute the Wyoming and federal numbers from your actual income and tell you before each one is due.
Book your free review before your next quarterly payment comes due. Deadlines for every other state are in our state tax deadlines index.