Tax Filing Deadlines for Your 2026 Return
Every federal, Indiana, and Kentucky deadline for the 2026 tax year, including why April 15, 2027 does not move and what is (and is not) changing for C corporation extensions.
The 2026 tax year closes on December 31, 2026, and the filing season for it runs from January through April 15, 2027. This post is the reference we use in our own office. Every date below is for calendar-year filers; if your business runs on a fiscal year, call us and we will map the dates for you.
Two details are easy to get wrong this cycle: the individual due date holds on Thursday, April 15, 2027 even though a Washington, DC holiday falls the very next day, and the one C corporation extension change for 2026 affects only June 30 fiscal-year corporations. Both are explained below.
Still on extension for 2025? Current deadlines
If your 2025 return is on extension, these dates come first:
- 2025 Form 1040 (extended): Thursday, October 15, 2026
- 2025 Kentucky Form 740 (extended): Thursday, October 15, 2026
- 2025 Indiana IT-40 (extended): Monday, November 16, 2026 (November 15 falls on a Sunday this year)
If we are preparing your extended return and are still waiting on documents, please get them to us through your Canopy portal as soon as you can.
Individual Returns (Form 1040)
Thursday, April 15, 2027 is the due date for your 2026 Form 1040 under IRC 6072(a). If you need more time, an automatic six-month extension under IRC 6081(a) moves the filing deadline to Friday, October 15, 2027.
An extension to file is not an extension to pay. Any tax you owe is still due April 15, 2027. Interest and the failure-to-pay penalty run from that date regardless of the extension.
Why April 15, 2027 does not move
You may see other sources claim the deadline shifts because of Emancipation Day, the District of Columbia holiday that has pushed the deadline in some past years. It does not shift in 2027.
IRC 7503 moves a due date only when the date itself falls on a Saturday, Sunday, or legal holiday, and the statute treats a DC legal holiday as a legal holiday for this purpose. In 2027, Emancipation Day is observed on Friday, April 16, the day after the deadline. April 15, 2027 is an ordinary Thursday, so the due date stands.
Estimated Tax Payments
If you are self-employed or have income without withholding, estimated payments are due under IRC 6654 on these dates:
| Payment | Due date |
|---|---|
| 2026 fourth quarter | Friday, January 15, 2027 |
| 2027 first quarter | Thursday, April 15, 2027 |
| 2027 second quarter | Tuesday, June 15, 2027 |
| 2027 third quarter | Wednesday, September 15, 2027 |
| 2027 fourth quarter | Tuesday, January 18, 2028 |
The January 2028 date is later than usual: January 15, 2028 is a Saturday and Monday, January 17 is Martin Luther King Jr. Day, so IRC 7503 pushes the payment to Tuesday, January 18.
Business Returns
Partnerships and S Corporations (Forms 1065 and 1120-S)
Monday, March 15, 2027 is the due date under IRC 6072(b). An extension under IRC 6081 moves it to Wednesday, September 15, 2027.
March 15 comes a full month before the individual deadline on purpose: your K-1 has to exist before your personal return can be finished. If your partnership or S corporation is going on extension, plan on your Form 1040 going on extension too.
C Corporations (Form 1120), calendar year
Thursday, April 15, 2027 is the due date under IRC 6072(a), and the extended due date is Friday, October 15, 2027.
This is not new. Calendar-year C corporations have had a six-month extension to October 15 since the 2016 due date changes took effect for 2017 filings, under Treas. Reg. 1.6081-3. The only C corporation extension change for 2026 is for corporations with a June 30 fiscal year end: for tax years beginning after December 31, 2025, their automatic extension drops from seven months to six months. If your corporation uses a June 30 year end, call us and we will confirm your dates.
Trusts and Estates (Form 1041)
Thursday, April 15, 2027 is the due date for calendar-year trusts and estates under IRC 6072(a). The extension under IRC 6081 is five and a half months, to Thursday, September 30, 2027.
Indiana
Indiana’s individual return (Form IT-40) is due April 15, 2027, the same day as the federal return.
The extension works differently from federal, and this is where firms outside Indiana routinely get it wrong. Indiana honors a federal extension and then allows one additional month beyond the federal extended due date. An extended IT-40 for 2026 is therefore due Monday, November 15, 2027, not October 15. The same rule applies if you file Indiana’s own extension request, Form IT-9. As with federal, the extension covers filing only. To avoid a penalty, Indiana expects at least 90% of the tax due to be paid by April 15, and the remaining balance, plus interest, to be paid by the extended due date.
Indiana rate change
Indiana’s individual income tax rate dropped from 3.00% for 2025 to 2.95% for 2026, with a further reduction to 2.90% scheduled for 2027 under the phase-down enacted in HEA 1001 (2023). County income tax rates are set separately by each county and are not affected.
Kentucky
Kentucky’s individual return (Form 740) tracks the federal calendar: due April 15, 2027, extended to October 15, 2027. Kentucky honors a federal extension automatically as long as a copy is attached to the return when filed, or you can request a Kentucky extension separately. Payment is still due April 15.
Kentucky rate change
Kentucky’s individual income tax rate dropped from 4.0% for 2025 to 3.5% for 2026 under House Bill 1 of the 2025 Regular Session. For 2027, the rate is expected to stay at 3.5%. Kentucky’s rate cuts are tied to revenue triggers under HB 1 (2022), and the state did not meet the trigger for another reduction, so the rate holds unless the legislature acts. We will confirm on revenue.ky.gov before filing season.
Quick Reference
| Return | Due | Extended |
|---|---|---|
| Form 1040 | Thu, April 15, 2027 | Fri, October 15, 2027 |
| Forms 1065 and 1120-S | Mon, March 15, 2027 | Wed, September 15, 2027 |
| Form 1120 (calendar year) | Thu, April 15, 2027 | Fri, October 15, 2027 |
| Form 1041 | Thu, April 15, 2027 | Thu, September 30, 2027 |
| Indiana IT-40 | Thu, April 15, 2027 | Mon, November 15, 2027 |
| Kentucky Form 740 | Thu, April 15, 2027 | Fri, October 15, 2027 |
Don’t Wait Until the Last Minute
Send your documents early. It gives us time to:
- Review your documents thoroughly
- Apply the new 2026 provisions correctly, including the two-rate mileage schedule and the charitable deduction changes
- Address any questions or issues that arise
- File your return without rushing
Need Help?
If you are unsure which deadlines apply to you, we are here to help. Contact us or get started today.