Estate 706 Deadline & Portability Clock by ReadyStack

Enter the date of death: get the 9-month Form 706 due date, the Form 4768 extended date, the earliest Pay.gov closing-letter request date, the five-year late-portability window, and the 2026 $15,000,000 exclusion math - in the browser tab you already have open.


Click Add to Firefox on this page. Nothing to unzip, no developer mode - the free version runs right away.

• Exclusion locked to the year of death — Applies the IRC 2010(c)(3) basic exclusion for the decedent's year of death - $15,000,000 for 2026 under OBBBA section 70106 and Rev. Proc. 2025-32, $13,990,000 for 2025 - instead of the repealed sunset figure that pre-2025 sources still quote.
• Nine-month due date and the Form 4768 extension — Counts the IRC 6075(a) nine-month Form 706 due date from the date of death and, when the automatic Form 4768 extension is elected, the six-month extended date, then shows days remaining from today.
• Earliest closing-letter request date — The IRS asks requesters to wait at least nine months after Form 706 is filed before ordering Letter 627 on Pay.gov; this dates that window from the actual filing date so nobody pays the user fee early.
• Five-year late portability election window — When the gross estate is under the filing threshold, Rev. Proc. 2022-32 allows a late DSUE portability election up to the fifth anniversary of death; the tool dates that anniversary and says when it does not apply.
• Month-one cost of slipping the date — Prices the IRC 6651(a)(1) failure-to-file addition - five percent of the tax for each month or fraction of a month - so the deadline has a dollar figure next to it, not just a date.
• CSV checklist export and deadline alarms — The paid layer writes the dated checklist to a .csv you can drop in the client file and sets Chrome alarms ahead of each date, so the clock keeps running after the tab is closed.

| You type | |
|---|---|
| Date of death | default 2026-03-15 |
| Gross estate + adjusted taxable gifts | default 18400000 |
| Marital, charitable and debt deductions | default 1200000 |
| DSUE ported from a predeceased spouse | default 0 |
| Automatic 6-month extension elected (Form 4768) | default True |
| Date Form 706 was actually filed | default 2026-12-10 |
| Today | default 2026-09-14 |

| It answers | |
|---|---|
| Basic exclusion for the year of death | USD |
| Exclusion + DSUE available | USD |
| Taxable estate after deductions | USD |
| Estimated federal estate tax (40% of the excess) | USD |
| Form 706 due (9 months, IRC 6075(a)) | |
| Extended due date (Form 4768) | |
| Days left to the operative deadline | days |
| Earliest closing-letter request (Pay.gov, $56) | |
| Late portability window closes (Rev. Proc. 2022-32) | |
| Month-one failure-to-file addition (IRC 6651(a)(1)) | USD |

Permissions requested: storage, downloads, alarms, notifications


Free: the calculation in the popup, no key, no limit. Full version ($60): download the result as .csv and deadline reminders - one licence key per person or team seat. Get it: https://getreadystack.com/api/buy/cl/polar_cl_YtqCQevdtAAEQeezD2b3ar2OEcxcI0xwnkXEn25tSMY


When you use the tool, the extension sends one anonymous count a day (the tool’s name only — no inputs, no personal data). Turn it off on the first page after install. Firefox asks first and sends nothing unless you allow it. A licence key is checked with the payment provider (Polar) only when you enter one.