Is the executor personally liable for the tax on the estate's failed 1031 exchange?

The tax belongs to the estate, and the executor's risk comes from paying anyone else first

When an exchange fails, the sale becomes taxable. For a sale the decedent closed before death, section 691(a)(1)(A) puts the proceeds in the estate's gross income when received, with the character they would have had in the decedent's hands; for a sale the estate itself made, the gain is the estate's directly. Either way it lands on Form 1041, with no separate penalty for the failure.

The federal priority statute changes who can be made to pay it. 31 U.S.C. 3713(a)(1)(B) gives a claim of the United States first place when "the estate of a deceased debtor, in the custody of the executor or administrator, is not enough to pay all debts of the debtor", and subsection (b) makes a representative "paying any part of a debt of the person or estate before paying a claim of the Government" liable "to the extent of the payment for unpaid claims of the Government".

Publication 559 applies the rule to executors: the personal representative of an insolvent estate is personally responsible for tax of the decedent or the estate if the representative knew, or should have known, of it before distributing or paying other debts, and no formal assessment is needed. An estate that hands all of the exchange proceeds to heirs and then cannot pay the tax is insolvent in that sense.

When the money arrives decides which return carries the tax, and how long the executor has to reserve it

The intermediary's agreement must restrict access to the proceeds under Reg. section 1.1031(k)-1(g)(6): the money cannot be released until after day 45 if nothing was identified, or after day 180 otherwise, as when the QI releases funds after a failed exchange explains. The estate reports the gain in the tax year it receives the money.

That year's Form 1041 is due on the 15th day of the fourth month after the estate's year ends under the Instructions for Form 1041, which also exempt a decedent's estate from estimated tax for any year ending within two years of the death. The exemption means no quarterly payments, not more time to pay: the balance is due with the unextended return. How that due date meets the exchange period is in the estate's Form 1041 due date and the 180 days.

So the executor has a defined window, from the day the proceeds arrive to the return's due date. Reserve the tax the day the money arrives; heirs can be paid from the balance above the reserve, which keeps the representative outside the priority statute even if the final number moves.

Hypothetical: $800,000 of proceeds, $500,000 of gain, and a distribution made too early

Hypothetical, round numbers. The decedent sold a rental for $800,000 and died on day 30 with nothing closed; the estate let the exchange lapse and received the proceeds on day 181. The gain is $500,000, of which $200,000 is prior depreciation. The CPA estimates the federal tax at roughly $129,000: 25% on the $200,000 of unrecaptured section 1250 gain, 20% on the remaining $300,000 at the compressed estate brackets, and 3.8% net investment income tax on the $500,000; state tax is extra, and how estates and trusts are taxed on real estate gains has the brackets.

If the executor distributes the full $800,000 to three heirs in December and the estate cannot pay the $129,000 in April, the priority statute lets the government recover from the executor personally up to the amount distributed. If instead the executor distributes $650,000 and holds $150,000 until the return is filed and paid, the estate stays solvent as to the federal claim and the executor has no exposure. Run your own figures with the estate's CPA; the reserve should cover state tax and interest too.

• Proceeds received: $800,000 on day 181.
• Safe sequence: reserve the tax, distribute the rest, file and pay, then release the reserve.

Form 56 and Form 5495 are the two filings that bound the executor's exposure

The Instructions for Form 56 require a fiduciary to notify the IRS of the relationship under section 6903 and to attach "current letters testamentary or a court certificate as proof of your court appointment", so that notices about the estate's return reach the executor.

Section 6905(a) lets an executor who has filed the decedent's income tax return apply in writing for release from personal liability; on paying the amount the IRS states, or nine months after the application if no notice comes, the executor "is discharged from personal liability for any deficiency in such tax thereafter found to be due". The IRS page for Form 5495 confirms that the executor of a decedent's estate or the fiduciary of a decedent's trust files that form. File it after the returns reporting the failed exchange, wait out the nine months or pay the stated amount, and only then make the final distribution.

What a prudent executor does between the failed exchange and the final distribution

The standard behind all of this is the one in Minnesota's section 524.3-703: the care "that would be observed by a prudent person dealing with the property of another". A representative who documents these steps has met it on the tax side.

• Get the intermediary's written confirmation of the release date and amount, and calendar the estate's Form 1041 due date from it.
• Have the CPA compute the federal and state tax within the month the money arrives, and move that sum to a separate estate account.
• File Form 56 with letters attached; distribute only the balance above the reserve and record the reason in the estate's accounting.
• After the return is filed, file Form 5495, and make the final distribution after the discharge or the nine-month period.
• Before the exchange fails, weigh completing it as a fiduciary decision; the owner died mid-exchange covers that choice, including the illiquidity and loss risk of a Delaware statutory trust interest used to close in time.