Disclaimer: This is general information, not legal or tax advice. For guidance tailored to your situation, consult a licensed attorney or a tax professional.

Detailed Answer — When an estate must file a federal return

Two separate federal filings can matter when someone dies: an income tax return for the estate or trust (Form 1041) and an estate tax return (Form 706). Which — if any — you must file depends on the estate’s income, the size of the decedent’s gross estate, and certain elections (for example, portability).

Form 1041: U.S. Income Tax Return for Estates and Trusts

The estate must file Form 1041 if, during the estate’s tax year, it has gross income of $600 or more, or if a beneficiary is a nonresident alien. Gross income includes interest, dividends, rental income, business income, and gains from the sale of assets. The fact that the estate made no distributions to beneficiaries does not by itself avoid the filing requirement. If the estate earned income (for example, bank interest or capital gains) totaling $600 or more, you generally must file Form 1041 and report that income to the IRS.

Authoritative IRS guidance and the official Form 1041 page: https://www.irs.gov/forms-pubs/about-form-1041. For practical filing guidance, see IRS Publication 559 (Survivors, Executors, and Administrators): https://www.irs.gov/publications/p559.

Form 706: Federal Estate (Gift) Tax Return

Form 706 (the federal estate tax return) is not the same as Form 1041. Form 706 is required only when the decedent’s gross estate meets or exceeds the federal filing threshold for the year of death, or when the personal representative elects portability (to transfer any unused exclusion to a surviving spouse). If the gross estate is below the applicable exclusion amount, no Form 706 is generally required unless you want to preserve portability for a surviving spouse.

See the IRS Form 706 information page for filing rules and deadlines (normally nine months after death, with possible extension): https://www.irs.gov/forms-pubs/about-form-706.

Decedent’s final individual return (Form 1040) and timing

The decedent’s final individual income tax return (Form 1040) covers income received up to the date of death. Income earned by the estate after death (interest, dividends, gain on sales, business income) is reported on the estate’s return (Form 1041) when required.

Practical examples

• Hypothetical A: The estate receives no distributions to beneficiaries and earns $250 in bank interest during administration. Because gross income is less than $600, Form 1041 generally is not required for that tax year, although you must keep records and may still file voluntarily.
• Hypothetical B: The estate earns $1,200 in interest and dividends while assets remain in estate accounts. Even though no distributions occurred, the estate’s gross income exceeds $600, so the fiduciary must file Form 1041 and pay or report tax on that income.
• Hypothetical C: The estate sells a piece of real estate during administration and realizes a $50,000 capital gain. That gain is taxable income to the estate and likely triggers a Form 1041 filing (and possibly state fiduciary returns).

Oklahoma-specific considerations

Oklahoma personal representatives must administer the estate under Oklahoma probate law. Procedural duties—such as taking inventory, filing probate pleadings, and providing accountings when required—flow from the Oklahoma Probate Code. For reference to the Oklahoma probate statutes (Title 58), see the Oklahoma Legislature’s statutes page: https://www.oklegislature.gov/osstatuestitle.html?title=58. The Oklahoma Tax Commission also addresses state filing obligations for estates and trusts: https://oklahoma.gov/tax.html.

Other practical points

• The estate generally needs an Employer Identification Number (EIN) to file Form 1041. Apply for an EIN online: https://www.irs.gov/businesses/small-businesses-self-employed/apply-for-an-employer-identification-number-ein-online.
• Filing deadlines: Form 1041 is generally due by the 15th day of the fourth month after the end of the estate’s tax year (for calendar-year estates, that is April 15). Form 706 is generally due nine months after the date of death; extensions are available in many cases. See the IRS instructions for exact deadlines and extension procedures.
• Even if no federal return is required, you must keep good records of all income, receipts, disbursements, and distributions. Oklahoma probate courts and beneficiaries may later request accounting information.

Helpful Hints

• Check gross income: Add all sources of estate income (interest, dividends, rents, business income, gains). If total gross income ≥ $600 in the estate tax year, plan to file Form 1041. See: Form 1041 and Publication 559.
• Decide on portability early: If the surviving spouse needs portability of the deceased’s unused exclusion, you may need to file Form 706 even if no tax is due. Review Form 706 guidance: Form 706.
• Apply for an EIN for the estate before filing any fiduciary returns: IRS EIN.
• Keep meticulous records of all estate activity. Even if no federal filing is required now, good records reduce problems later with beneficiaries, the probate court, or tax authorities.
• Consult a CPA or tax attorney if the estate sells assets, operates a business, or earns substantial income during administration. These situations frequently create complex tax questions.
• Review Oklahoma probate procedures and any state fiduciary income tax rules. See Oklahoma Title 58 statutes: Title 58 (Probate), and the Oklahoma Tax Commission for state filings: Oklahoma Tax Commission.