Federal estate tax reporting requirements kick in when the executor of a decedent’s estate must file IRS Form 706, and for anyone dying in 2026 that duty attaches once the gross estate plus lifetime taxable gifts exceeds $15 million.1Internal Revenue Service. What’s New — Estate and Gift Tax The return is due nine months after the date of death, along with any tax owed. Executors of smaller estates sometimes file anyway to lock in benefits for the surviving spouse or family trusts, and that choice can be worth millions.
Who Has to File Form 706
The filing trigger is the size of the gross estate combined with taxable gifts the decedent made during life. If that total tops the basic exclusion amount for the year of death, the executor must file. In 2026 that amount is $15 million.1Internal Revenue Service. What’s New — Estate and Gift Tax The figure is set by Section 2010(c)(3) of the tax code and will adjust for inflation starting in 2027.2Office of the Law Revision Counsel. 26 U.S. Code 2010 – Unified Credit Against Estate Tax
The gross estate is broader than what passes through probate. It includes life insurance proceeds payable to the estate or over which the decedent held incidents of ownership, retirement accounts, jointly held property, revocable trust assets, and some property transferred within three years of death.3Internal Revenue Service. Estate Tax The obligation to file falls on the executor or personal representative, and it does not go away just because deductions will wipe out the tax.4Internal Revenue Service. Publication 559 – Survivors, Executors, and Administrators
When Filing Is Optional But Still Smart
Plenty of estates below $15 million file Form 706 by choice. The main reason is portability. Filing lets the surviving spouse inherit whatever share of the decedent’s exclusion went unused, so a couple can shield up to $30 million combined.5Internal Revenue Service. Instructions for Form 706 – Section: Part VI — Portability of Deceased Spousal Unused Exclusion (DSUE) Skip the filing and that unused exclusion disappears.
An executor who misses the standard nine-month window still has a second chance. Revenue Procedure 2022-32 allows estates that were not otherwise required to file to elect portability by submitting a complete Form 706 anytime within five years of the decedent’s death.6Internal Revenue Service. Revenue Procedure 2022-32 The return must be marked at the top with the words “FILED PURSUANT TO REV. PROC. 2022-32 TO ELECT PORTABILITY UNDER § 2010(c)(5)(A).” No user fee. No private letter ruling required.
The other common reason to file voluntarily is to allocate the generation-skipping transfer (GST) exemption. Every individual gets a GST exemption equal to the basic exclusion amount, and the executor allocates it on Schedule R.7Internal Revenue Service. Schedule R (Form 706) Without an affirmative allocation, IRS “deemed allocation” rules take over, and they may not match what the family wanted for trusts benefiting grandchildren. Errors here surface decades later when a trust distribution is hit with the flat 40% GST tax.
The Nine-Month Deadline
Form 706 and any tax owed are due nine months after the date of death.8Internal Revenue Service. Private Letter Ruling 200419005 – Section: LAW and ANALYSIS A March 1 death produces a December 1 return. When the deadline lands on a weekend or holiday, it moves to the next business day.
An automatic six-month filing extension is available by submitting Form 4768 before the original deadline expires. No explanation is needed, and the new deadline lands 15 months after death. That extra time often matters for estates with hard-to-value business interests or ongoing disputes over asset ownership.
Here is the trap: the extension only extends the time to file. It does not extend the time to pay. The IRS still expects payment of the estimated tax by the original nine-month mark. When the exact figure is not yet known, the safe move is to overpay and claim a refund on the finished return. Underpayment triggers interest and penalties running from the original due date.
What Goes on Form 706
The return is a detailed inventory of everything the decedent owned or held an interest in at death. Separate schedules cover real estate, stocks and bonds, mortgages and notes, cash accounts, life insurance, jointly held property, and miscellaneous assets like vehicles and collectibles. Every item is reported at fair market value, meaning the price a willing buyer and seller would agree to at arm’s length.
Written appraisals from qualified experts are required for household goods and personal property with artistic or intrinsic value totaling more than $3,000.9eCFR. 26 CFR 20.2031-6 – Valuation of Household and Personal Effects Closely held business interests, commercial real estate, and unusual holdings such as mineral rights or intellectual property also generally need professional appraisals. If the IRS challenges a valuation and no appraisal supports it, the estate almost always loses that argument.
The executor also reports beneficiary information: names, Social Security numbers, relationship to the decedent, and estimated share.10Internal Revenue Service. Instructions for Form 706 – Section: Part IV — General Information This data lets the IRS verify marital and charitable deductions and track the basis of inherited assets.
Deductions That Shrink the Taxable Estate
The taxable estate equals the gross estate minus allowable deductions. Common ones include funeral expenses, legal and accounting fees for administering the estate, casualty losses during administration, and debts the decedent owed at death.11Internal Revenue Service. Instructions for Form 706 – Section: Schedule J Two others tend to dominate large estates: an unlimited marital deduction for transfers to a U.S. citizen spouse, and a charitable deduction for transfers to qualifying organizations. Between those, many estates over the filing threshold owe no tax. Whatever remains is taxed at graduated rates topping out at 40%.
Valuation Elections That Can Cut the Bill
Alternate Valuation Date
If asset values dropped after death, the executor can value the estate as of six months after death instead. Property sold or distributed before the six-month mark takes its value on the transaction date. The election is only available when it reduces both the gross estate and the total estate tax.12Office of the Law Revision Counsel. 26 U.S. Code 2032 – Alternate Valuation It has to be made on a timely filed return (including extensions), cannot be filed more than a year after the original due date, and is irrevocable once made. The trade-off is a lower stepped-up basis for beneficiaries.
Special Use Valuation for Farms and Businesses
Section 2032A lets qualifying farm or closely held business real property be valued at its actual use rather than its highest-and-best-use market price. A working farm with $8 million in development value might come in at $3 million as agricultural land. The reduction is capped at an inflation-adjusted amount built off a $750,000 statutory base. Eligibility requires the property to make up a significant share of the estate, to have been used in a qualifying activity for several years before death, and to pass to qualified heirs who continue that use. A sale or change of use within ten years triggers a recapture tax.
Paying the Tax
Form 706 is paper-filed. There is no electronic option. The complete return goes to the IRS in Kansas City with a certified copy of the death certificate, copies of the will and any trust documents, appraisals, and documentation for claimed deductions:
Department of the Treasury
Internal Revenue Service
Kansas City, MO 6499913Internal Revenue Service. Where to File – Forms Beginning With the Number 7
Certified mail or a designated private delivery service creates a postmark record that proves timely filing. Given the size of late-filing penalties, that receipt is cheap insurance. Payment is due when the return is submitted, and the IRS accepts payment through the Electronic Federal Tax Payment System or by check mailed with the return.
Installments for Closely Held Business Estates
When a closely held business makes up more than 35% of the adjusted gross estate, Section 6166 lets the executor defer the first installment of tax attributable to that interest for up to five years and then spread the balance over up to ten annual installments. The full payment window can stretch about 14 years, with only interest due during the initial deferral.14Office of the Law Revision Counsel. 26 U.S. Code 6166 – Extension of Time for Payment of Estate Tax Where Estate Consists Largely of Interest in Closely Held Business A reduced interest rate applies to a portion of the deferred tax. For family businesses and farms with illiquid wealth, this election is often what makes keeping the operation possible. The election must be made on a timely filed return.
Penalties for Missing the Deadline
The penalty structure escalates quickly:
- Late payment runs 0.5% of the unpaid tax for each month or partial month the balance is outstanding, capped at 25%.15Internal Revenue Service. Failure to Pay Penalty
- Late filing runs 5% of the unpaid tax per month, capped at 25%. When both apply in the same month, the filing penalty drops to 4.5% and the payment penalty stays at 0.5%, keeping the combined monthly hit at 5%.15Internal Revenue Service. Failure to Pay Penalty
- Interest compounds daily on unpaid tax from the original due date. The underpayment rate for early 2026 is 7% annually.16Internal Revenue Service. Interest Rates Remain the Same for the First Quarter of 2026
On an estate owing $2 million, filing five months late without an extension could produce $500,000 in penalties alone, before interest. If assets have already been distributed to beneficiaries, the executor is personally liable for those amounts.
Reasonable cause relief exists. The IRS asks whether the executor exercised ordinary business care and prudence but was still unable to comply. Serious illness or death of the person responsible for filing, inability to obtain records despite diligent effort, fire or natural disaster, and reliance on incorrect written advice from the IRS itself all qualify.17Internal Revenue Service. Introduction and Penalty Relief Forgetfulness and general overwhelm do not. The IRS also weighs the executor’s compliance history over the prior three years.
Reporting Basis to Beneficiaries
Executors who file Form 706 have a separate obligation many miss: filing Form 8971 and giving each beneficiary a Schedule A showing the estate tax value of the assets they received. That statement fixes the beneficiary’s basis for when the property is later sold. Form 8971 is due 30 days after the Form 706 filing deadline (including extensions) or 30 days after Form 706 is actually filed, whichever comes first.18Internal Revenue Service. Instructions for Form 8971 and Schedule A A beneficiary who never receives the statement must use a basis of zero on sale, which produces a much larger capital gain.
State Estate and Inheritance Taxes
Federal is not the whole picture. Roughly a dozen states and the District of Columbia levy their own estate taxes, and several other states impose inheritance taxes on beneficiaries. State exemption thresholds are often far lower than the federal amount, sometimes as low as $1 million, so an estate that owes nothing federally can still face a substantial state bill. One state applies both an estate and an inheritance tax. State deadlines and forms are separate from the federal return, and the executor needs to check the rules in every state where the decedent owned real property or maintained a domicile.
Closing Out the Estate with the IRS
After the IRS reviews the return, the executor can request Letter 627, the Estate Tax Closing Letter, confirming that the federal estate tax liability has been resolved. The letter is not automatic. The executor pays a $56 user fee through Pay.gov and submits the request after confirming that transaction code 421 has posted to the estate’s account transcript, which indicates the return has been accepted or examination is complete.19Internal Revenue Service. Frequently Asked Questions on the Estate Tax Closing Letter
The IRS does not publish processing estimates. When the transaction code is already on file at the time of the request, research typically takes about three weeks before the letter is assigned for production. When the code has not yet posted, the IRS rechecks roughly every 60 days.19Internal Revenue Service. Frequently Asked Questions on the Estate Tax Closing Letter Many executors wait a year or more from filing to receive the letter. Distributing every asset before it arrives carries risk, because if the IRS later adjusts the tax upward the executor can be personally on the hook for the shortfall.