Form 15644 due date: your filing window by fiscal year-end
Form 15644 has no single due date. You file it in a window: no earlier than 90 days and no later than 30 days before your central organization’s fiscal year ends.
Checked against IRS sources on Oct 23, 2026
The rule
File Form 15644 at least 30 days, but no more than 90 days, before the end of the central organization’s tax year (Rev. Proc. 2026-8 §7.01). Use the same tax year as on the central’s own Form 990 or 990-EZ (Form 15644 instructions, item a).
You file every year, even when nothing changed. In that case you check “No reportable change” (Rev. Proc. 2026-8 §7.02(5)). You can also file an interim update at any time, for example to remove a chapter.
Windows by fiscal year-end
| Fiscal year ends | Next window | The window after |
|---|---|---|
| Jan 31 | Nov 2, 2026 – Jan 1, 2027 | Nov 2, 2027 – Jan 1, 2028 |
| Feb 28/29 | Nov 30, 2026 – Jan 29, 2027 | Dec 1, 2027 – Jan 30, 2028 |
| Mar 31 | Dec 31, 2026 – Mar 1, 2027 | Jan 1 – Mar 1, 2028 |
| Apr 30 | Jan 30 – Mar 31, 2027 | Jan 31 – Mar 31, 2028 |
| May 31 | Mar 2 – May 1, 2027 | Mar 2 – May 1, 2028 |
| Jun 30 | Apr 1 – May 31, 2027 | Apr 1 – May 31, 2028 |
| Jul 31 | May 2 – Jul 1, 2027 | May 2 – Jul 1, 2028 |
| Aug 31 | Jun 2 – Aug 1, 2027 | Jun 2 – Aug 1, 2028 |
| Sep 30 | Jul 2 – Aug 31, 2027 | Jul 2 – Aug 31, 2028 |
| Oct 31 | Aug 2 – Oct 1, 2027 | Aug 2 – Oct 1, 2028 |
| Nov 30 | Sep 1 – Oct 31, 2026 | Sep 1 – Oct 31, 2027 |
| Dec 31 | Oct 2 – Dec 1, 2026 | Oct 2 – Dec 1, 2027 |
If your year ends on another date, such as a 52–53-week year, count back from your actual year-end. The IRS hasn’t said whether a weekend or holiday extends the window, so don’t count on extra time.
A separate date: before Jan 22, 2027
Group exemption letters that existed on Jan 20, 2026 must complete the transition cleanup before Jan 22, 2027 (Rev. Proc. 2026-8 §12.02(2)). If your annual window opens after that date, file the cleanup as an interim update. See the cleanup checklist.
Find your own group’s window
Sources
- IRS, Rev. Proc. 2026-8 (PDF): §§7.01, 7.02(5) and 12.02.
- IRS, Form 15644 and its instructions (Rev. 10-2026, PDF).
General information from public IRS documents, checked Oct 23, 2026. Not tax or legal advice. Not affiliated with the IRS.