Reminders

Due dates. Form 3520 is due by the 15th day of the 4th month following the end of the taxpayer’s tax year. However, taxpayers who live and work outside the United States have until the 15th day of the 6th month to file the form. If an extension has been requested, check box 1k and include the form number of the tax return for which the extension applies. See When and Where To File , later.

Form 3520-A is due by the 15th day of the 3rd month after the end of the foreign trust’s tax year. However, a substitute Form 3520-A attached to a U.S. owner’s Form 3520 is due the same day as Form 3520. The U.S. owner must check the “Substitute Form 3520-A” checkbox on the top of Form 3520-A that is attached to Form 3520. See Instructions for Form 3520-A .

Assessment period. If a complete Form 3520 is not filed by the due date, including extensions, the time for assessment of any tax imposed with respect to any event or period to which the information required to be reported in Parts I through III of such Form 3520 relates will not expire before the date that is 3 years after the date on which the required information is reported. See section 6501(c)(8).

Continuous-use revision. Use these instructions for tax year 2025 and subsequent years until a superseding revision is issued.