How Do I File Taxes for a Deceased Person in Oklahoma?

Oklahoma requires a final state income tax return for the decedent alongside the federal Form 1040; a federal estate tax return (Form 706) is required only for estates above $15,000,000.

State

Approximate Estate Value

Estate Earns Income

YesNo

Date of Death

Two returns are due.

IRS Form 1040 and Form 511 (Oklahoma Resident Individual Income Tax Return).

Federal

Final income tax return

A final federal income tax return is required for income earned from January 1 through the date of death.

Form: IRS Form 1040
Due: April 15 following year of death

Write "DECEASED," the decedent's name, and the date of death across the top of the return. If filing jointly with a surviving spouse, include both incomes. Attach Form 1310 to claim a refund, unless you are the surviving spouse filing a joint return or a court-appointed personal representative attaching a copy of the court certificate to the original return.

IRS Form 1040 File online

Oklahoma

Final income tax return

A final state return is required for income earned through the date of death.

Form: Form 511 (Oklahoma Resident Individual Income Tax Return)
Due: April 15 following the year of death (April 20 if the Oklahoma return is filed electronically)

The executor, administrator, or surviving spouse files the decedent's final Form 511. OTC's instruction is verbatim: "If a taxpayer died before filing a return, the executor, administrator, or surviving spouse may have to file a return for the deceased.

Form 511 (Oklahoma Resident Individual Income Tax Return)File online

Tax clearance

No tax clearance is required in Oklahoma

Oklahoma does not require a state tax clearance certificate for estate distribution. The estate tax was repealed for deaths on or after January 1, 2010 (Laws 2006, 2nd Extra. Sess., c. 42, § 6 (HB 1172), repealing 68 O.S. §§ 801–803 and 805–825).

Not required

Federal estate income tax return: IRS Form 1041 is only required if the estate earns $600 in gross income or more during administration.
Federal estate tax return: The estate value ($0) is below the federal exemption of $15,000,000. IRS Form 706 is generally not required.
Oklahoma estate income tax return: A fiduciary return is only required if the estate earns income above the filing threshold (Every resident estate or trust must file. Nonresident estates/trusts file Form 513-NR if they have Oklahoma taxable income (rents/royalties, business, partnership or S-corp income, or sales of Oklahoma real property) — 68 Okla. Stat. § 2368(G), § 2362).

General information about tax filing requirements after a death, not tax or legal advice. Consult a licensed tax professional for tax questions. Data verified Sep 15, 2026

At minimum, a final federal income tax return (Form 1040) for income earned through the date of death, and Oklahoma requires a final state income tax return (Form 511) as well. If the estate earns income during administration, a federal fiduciary return (Form 1041) and an Oklahoma fiduciary return (Form 513) may also be required.

The final federal income tax return is due April 15 following year of death. The final Oklahoma return is due April 15 following the year of death (April 20 if the Oklahoma return is filed electronically). The Oklahoma fiduciary return is due April 15 for calendar-year estates; the 15th day of the fourth month following the close of the taxable year for fiscal-year estates.

No. Oklahoma does not require a state tax clearance certificate for estate distribution. The estate tax was repealed for deaths on or after January 1, 2010 (Laws 2006, 2nd Extra. Sess., c. 42, § 6 (HB 1172), repealing 68 O.S. §§ 801–803 and 805–825). Every tax obligation is still settled before the final distribution.

No. Oklahoma imposes no state estate tax and no inheritance tax. The tax filings after a death are the income tax returns (the final return and, where the estate earns income, the estate income tax return). Only the federal estate tax applies, and only to an estate above $15,000,000.

Yes. Estate size does not change the final income tax return: a final Form 1040 is filed whatever the estate is worth if the decedent had income. What a smaller estate avoids is the federal estate tax return (Form 706), due 9 months after date of death (6-month extension available) and required only above $15,000,000.

Tax Filing After Death in Oklahoma

Tax obligations in Oklahoma include filing the deceased's final state and federal income tax returns. If the estate generates income (interest, dividends, rent) before distribution, a fiduciary return is also required. A federal estate tax return (Form 706) is required only for estates above the federal exemption of $15,000,000.

Oklahoma does not impose a state estate tax or inheritance tax. The primary post-death tax obligations are income tax related — the final return and any fiduciary returns needed during estate administration.

Missing tax deadlines can result in penalties and interest that reduce the estate's value. The final Oklahoma income tax return is due April 15 following the year of death (April 20 if the Oklahoma return is filed electronically). The estate settlement plan for Oklahoma includes all filing dates in order.

SimplyTrust Editorial·Updated September 20, 2026

Legal Sources

Data sourced from Oklahoma statutes and official state code. How we research.

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