Federal estate taxes are due nine months after the decedent’s date of death. That single deadline covers both filing Form 706 and paying the tax in full. If the decedent died on March 10, both the return and the payment are due December 10 of the same year. An executor who needs more time to prepare the paperwork can get a six-month filing extension, but the money is still expected by the original date.
How the Nine-Month Deadline Is Calculated
The due date lands on the day in the ninth month that numerically matches the date of death.1Office of the Law Revision Counsel. 26 USC 6075 – Time for Filing Estate and Gift Tax Returns A January 31 death produces an October 31 deadline. When the ninth month has no matching day (a May 31 death runs into February), the deadline moves to the last day of that month.
Payment is due on the same date as the return. The IRS expects the full liability paid by the end of the nine-month window regardless of whether the estate has finished selling assets or resolved valuation questions. The top marginal rate is 40 percent of the taxable estate above the exemption, so the amounts can be significant.2Center on Budget and Policy Priorities. Policy Basics: The Federal Estate Tax An estate worth $20 million with a $15 million exemption could owe up to $2 million in federal tax alone.
Whether the Estate Has to File at All
An executor must file Form 706 when the decedent’s gross estate exceeds the basic exclusion amount for the year of death. For deaths in 2026, that exclusion is $15 million per person, a figure set by the One, Big, Beautiful Bill signed into law on July 4, 2025.3Internal Revenue Service. What’s New – Estate and Gift Tax The gross estate includes real estate, bank accounts, investments, retirement accounts, life insurance proceeds, and business interests. The threshold is reduced by any taxable gifts the decedent made after 1976, so an executor whose decedent gave away $2 million during life would need to file if the remaining estate exceeds $13 million.4Office of the Law Revision Counsel. 26 USC 6018 – Estate Tax Returns
Surviving spouses have a reason to file even when the estate is well below the threshold. A timely Form 706 preserves the deceased spousal unused exclusion (DSUE), letting the survivor claim whatever exemption the first spouse did not use. The standard deadline for that election is the same nine months plus any extension. Executors who miss it get a second chance under a simplified late-election process available within five years of the date of death, provided the estate was not otherwise required to file.5Internal Revenue Service. Rev. Proc. 2022-32 No user fee applies to the simplified request.
Filing Extensions Versus Payment Extensions
An executor who needs more time to prepare the return can request an automatic six-month filing extension by submitting IRS Form 4768 before the original nine-month deadline.6eCFR. 26 CFR 20.6081-1 – Extension of Time for Filing the Return This is the single most misunderstood piece of estate tax timing. The extension buys more time for paperwork; it does not extend the deadline to pay. The executor still needs to estimate the total liability and send that amount by the original due date. File Form 4768 but pay nothing, and interest and late-payment penalties start running immediately.
A separate payment extension exists under a different provision. The IRS may grant additional time to pay for reasonable cause, such as when estate assets are illiquid and cannot be quickly converted to cash.7Office of the Law Revision Counsel. 26 USC 6161 – Extension of Time for Paying Tax For estate tax specifically, that extension can run up to 10 years from the original due date when reasonable cause is shown. Payment extensions are not automatic. They require a separate request on Form 4768 and IRS approval.
Penalties and Interest for Missing the Deadline
Two penalties apply when an estate misses its deadline, and they can run at the same time.
- Late filing: 5 percent of the unpaid tax for each month or partial month the return is overdue, capped at 25 percent total.8Internal Revenue Service. Failure to File Penalty
- Late payment: 0.5 percent of the unpaid tax per month, also capped at 25 percent.9Internal Revenue Service. Topic No. 653, IRS Notices and Bills, Penalties and Interest Charges
On top of both penalties, the IRS charges interest on any unpaid balance. The rate adjusts quarterly and equals the federal short-term rate plus three percentage points for individual taxpayers. For the first quarter of 2026, that rate was 7 percent; it dropped to 6 percent for the second quarter.10Internal Revenue Service. Quarterly Interest Rates Interest compounds daily. If cash is short, file on time anyway and pay what you can. That avoids the much larger 5-percent-per-month filing penalty and stops the smaller clock from running against the full balance.
Paying Over Time When the Estate Owns a Closely Held Business
Estates built around a closely held business face a particular hardship: the tax bill can be substantial while most of the value sits in something that cannot be sold quickly. Congress created a special installment plan for that situation. If the value of the business interest exceeds 35 percent of the adjusted gross estate, the executor can elect to spread the tax attributable to the business over up to 10 annual installments.11Office of the Law Revision Counsel. 26 USC 6166 – Extension of Time for Payment of Estate Tax Where Estate Consists Largely of Interest in Closely Held Business
Under the election, the executor can defer the first installment for up to five years after the original payment deadline, paying only interest during that period. After the deferral ends, the tax is paid in equal annual installments with interest. The total payout can stretch as long as 14 years from the original due date. The qualification rules are strict. The business must be a sole proprietorship, a partnership with 45 or fewer partners, or a corporation with 45 or fewer shareholders, along with other requirements. The election must be made on a timely filed Form 706, so decisions about it belong at the front of the process, not the back.
Other Deadlines the Executor Owns
The estate tax return is the deadline most executors know about, but two other tax filings carry their own dates and their own penalties.
- Decedent’s final income tax return (Form 1040). This covers income the decedent earned from January 1 through the date of death. It is due on the normal April 15 deadline of the following year. A decedent who died in August 2026 has a final 1040 due April 15, 2027.
- Estate income tax return (Form 1041). After death, the estate itself may earn income from interest, dividends, rent, or asset sales. That income gets reported on Form 1041. For estates using a calendar year, the return is due April 15 of the following year. Estates can also elect a fiscal year, in which case the return is due on the 15th day of the fourth month after the fiscal year ends.12Internal Revenue Service. File an Estate Tax Income Tax Return
Both returns are easy to overlook while the executor is focused on the estate tax. The penalties for missing them match what any individual taxpayer would face. Keeping a calendar of all three deadlines from the start prevents unpleasant surprises.
State Deadlines Are Separate
Federal estate tax is only part of the picture. Thirteen states and the District of Columbia impose their own estate taxes, and five states levy inheritance taxes on beneficiaries. A few states impose both. These state-level taxes operate independently and often apply to estates well below the federal threshold. Exemptions run from $1 million to $5 million in most states with an estate tax, though a handful have matched or exceeded the federal exemption. Oregon begins taxing estates above $1 million; Massachusetts starts at $2 million.
Most states with an estate tax follow the federal nine-month deadline, but some tie the due date to probate proceedings or set their own timeline. Estate taxes are paid by the estate before distribution; inheritance taxes are owed by the beneficiary who receives property, and states that impose them often exempt close family members and set rates based on the beneficiary’s relationship to the decedent. Because rules vary, executors handling estates in states with their own death taxes should confirm deadlines with the state tax agency early. State penalties and interest run separately from anything the IRS charges.