When Are Trust Taxes Due? Filing, Extensions, and the 65-Day Rule

For a trust on the calendar year, federal income tax is due when Form 1041 is due: April 15 of the year after the tax year ends. Quarterly estimated tax payments are due April 15, June 15, September 15, and January 15 of the following year. If April 15 falls on a weekend or federal holiday, the deadline moves to the next business day. Almost all trusts are required by federal law to use a calendar tax year, so these dates apply to the vast majority of filers.¹²

Does the Trust Have to File at All

Before worrying about the deadline, confirm the trust owes a return. A fiduciary must file Form 1041 for a domestic trust if any one of these is true:

The trust has any taxable income for the year, even one dollar.
The trust has gross income of $600 or more, regardless of taxable income after deductions.
Any beneficiary is a nonresident alien, no matter how small the income.

These thresholds come straight from the Form 1041 instructions.³

One boundary worth naming: a grantor trust whose entire assets are treated as owned by the grantor may not need its own 1041. The trustee can elect to report all trust income directly on the grantor’s individual return, provided conditions are met — the trust cannot hold assets outside the United States, and the grantor must be a U.S. person on a calendar tax year, among others.⁴ If only part of the trust is grantor-owned, the grantor portion is reported on a statement attached to Form 1041 rather than on the return itself.

Quarterly Estimated Tax Payment Dates

A trust that expects to owe $1,000 or more in tax after subtracting withholding and credits must make quarterly estimated payments using Form 1041-ES.⁵ For a calendar-year trust:

First installment: April 15
Second installment: June 15
Third installment: September 15
Fourth installment: January 15 of the following year

The January 15 payment can be skipped if the fiduciary files the completed Form 1041 by January 31 and pays the entire remaining balance with the return.⁵

Even if the payments fall short of the actual tax bill, the fiduciary avoids an underpayment penalty by meeting one of two safe harbors: paying at least 90% of the current year’s tax, or 100% of the tax shown on the prior year’s return.⁶ The prior year must have been a full 12-month period and the trust must have filed a return for it. Note that the two-year exemption from estimated tax that estates enjoy does not extend to most trusts.

The Narrow Fiscal-Year Exception

Only one common route lets a trust step off the calendar year. When the grantor of a revocable trust dies, the fiduciary can file Form 8855 to elect under Section 645 to have the trust treated as part of the decedent’s estate for tax purposes. Because estates may choose a fiscal year, this election effectively lets the combined entity end its tax year on the last day of any month, so long as that date falls before the first anniversary of the grantor’s death. The election is irrevocable and requires the signatures of the trustee and the estate’s executor if one exists. Tax-exempt trusts and wholly charitable trusts are the other exceptions written into the code itself.

Extending the Filing Deadline

A fiduciary who cannot complete Form 1041 by April 15 can request an automatic five-and-a-half-month extension by filing Form 7004 on or before the original due date.⁷ For a calendar-year trust, that pushes the filing deadline to September 30.

An extension to file is not an extension to pay. The fiduciary must estimate the total tax owed and send that amount with Form 7004. Any balance still unpaid after April 15 accrues both the late-payment penalty and interest, even when the extension itself is valid.⁷

Schedule K-1 Deadline for Beneficiaries

The filing deadline is also a delivery deadline. Each beneficiary who receives a distribution or an allocation of income must get a copy of Schedule K-1 (Form 1041) on or before the date the trust’s return is due. For a calendar-year trust, that means K-1s must reach beneficiaries by April 15.³ If the fiduciary obtains a filing extension, the K-1 deadline extends with it.

Failing to provide a K-1 on time, or providing one with incorrect information, can bring a penalty of $340 per statement. If the failure is intentional, the penalty rises to $680 per statement or 10% of the total amounts required to be reported, whichever is greater.³ Beneficiaries need these forms to file their own returns, so timely delivery protects both sides.

Penalties and Interest for Missing a Deadline

The IRS charges separate penalties for filing late and for paying late. Both can apply at the same time, though the failure-to-file penalty is reduced by the failure-to-pay penalty when they overlap in the same month.⁸

Failure to file: 5% of the unpaid tax for each month or partial month the return is late, up to a maximum of 25%.⁸
Failure to pay: 0.5% of the unpaid tax for each month or partial month the balance remains outstanding, up to a maximum of 25%.⁷
Interest on any unpaid balance, compounded daily. The rate is set quarterly; for the first quarter of 2026, the underpayment rate is 7%.⁹

The failure-to-file penalty is ten times steeper than the failure-to-pay penalty. A fiduciary who cannot pay in full should still file on time. Filing late and paying late together is far more expensive than filing on time and paying what you can.

Missed estimated payments carry their own bill. The IRS calculates an underpayment penalty based on the shortfall, how long it went unpaid, and the published quarterly underpayment rate.¹⁰ Hitting one of the two safe harbors avoids it entirely, and the penalty does not apply if the trust ends up owing less than $1,000 after credits and withholding.⁵

A Post-Year-End Lever: The 65-Day Rule

There is one useful deadline that falls after the tax year has already ended. Under Section 663(b), a fiduciary who realizes the trust retained too much taxable income can treat distributions made within the first 65 days of the new year as if they were paid on the last day of the prior year. That lets the trust claim an income distribution deduction on the earlier return and shift the tax to beneficiaries, who often pay at lower individual rates than the trust’s compressed brackets.¹¹

To make the election, the fiduciary checks the box on Schedule B of Form 1041. The return must be filed by its due date, including extensions, for the election to be valid. It has to be made separately each year, it does not carry over, and it is irrevocable once made. The amount eligible is capped at the trust’s distributable net income for the year, reduced by other distributions already made during that year.

1
Office of the Law Revision Counsel. 26 USC 644 – Taxable Year of Trusts
2
Office of the Law Revision Counsel. 26 USC 6072 – Time for Filing Income Tax Returns
3
IRS.gov. 2025 Instructions for Form 1041 and Schedules A, B, G, J, and K-1
4
eCFR. 26 CFR 1.671-4 – Method of Reporting
5
Internal Revenue Service. 2026 Form 1041-ES
6
Office of the Law Revision Counsel. 26 USC 6654 – Failure by Individual To Pay Estimated Income Tax
7
Internal Revenue Service. Instructions for Form 7004
8
Internal Revenue Service. Failure to File Penalty
9
Internal Revenue Service. Quarterly Interest Rates
10
Internal Revenue Service. Underpayment of Estimated Tax by Individuals Penalty
11
eCFR. 26 CFR 1.663(b)-1 – Distributions in First 65 Days of Taxable Year