Form 3520 Due Date: When to File, How to Extend, and What to Do If You're Late

Form 3520 and Form 3520-A are forms that a person or entity may be required to submit under IRS requirements. If a required form is not submitted on time and there is no extension, a CP15 notice will be issued if the IRS catches the problem. The CP15 notice is what triggers the penalty assessment. Not every late filing results in a CP15 notice or a penalty.

If you have a foreign trust transaction, foreign trust ownership, a trust distribution, or certain foreign gifts, knowing the Form 3520 due date is essential. The rules are technical, but careful planning protects you. Our compliance guide to Form 3520-A walks through the reporting rules in depth.

IRS Relief for Taxpayers in Israel: Form 3520 Deadline Postponed to September 30, 2027

Affected taxpayers in Israel, the West Bank, or Gaza have a postponed Form 3520 deadline of September 30, 2027. IRS assistance hotlines: 866-562-5227, or 267-941-1000 for international callers.

Under Notice 2026-63 and the IRS newsroom release IR-2026-116, affected taxpayers — including those whose principal residence or principal place of business is in Israel, the West Bank, or Gaza, and the other affected-taxpayer categories described by the IRS — have this postponement when the due date falls within the relief window. Form 3520 is covered under Rev. Proc. 2018-58, section 12, item 49.

What Is the Standard Form 3520 Due Date for Calendar-Year Taxpayers?

Form 3520 is generally due by the 15th day of the fourth month following the end of your tax year. For most calendar-year individuals, the standard due date is April 15. If the due date falls on a Saturday, Sunday, or legal holiday, your filing deadline moves to the next business day.

Form 3520 is an information return filed separately from your U.S. income tax return. The official IRS Instructions for Form 3520 explain what must be reported.

When to File Form 3520 If You Live and Work Outside the United States

Qualifying U.S. citizens and residents who live and work outside the United States and Puerto Rico generally have until the 15th day of the sixth month following the end of the tax year. For a calendar-year individual, this usually means June 15. The rule can also cover certain military service abroad. You must include a statement with Form 3520 showing that you meet the condition. The additional time does not eliminate complete and accurate reporting.

How to Extend Form 3520 and How It Differs From Form 3520-A

There is no standalone extension form for Form 3520; it generally follows an approved extension of your related income tax return.

If you requested an extension, check box 1k on Form 3520 and enter the related income tax return form number, such as Form 1040. When your income tax return extension is approved, the Form 3520 due date is extended by the same amount of time.

Form 3520-A follows a different process. An extension of your income tax return does not extend Form 3520-A. The foreign trust must file Form 7004 under the foreign trust’s taxpayer identification number by the original Form 3520-A deadline.

What Is the Separate Form 3520-A Deadline for a Foreign Trust?

Form 3520-A is generally due by the 15th day of the third month after the end of the foreign trust’s tax year. For a trust with a December 31 year-end, the deadline is March 15.

If the trust does not file Form 3520-A, the U.S. owner may need to prepare a substitute Form 3520-A and attach it to Form 3520. The substitute form is due on the same date as Form 3520, including any valid extension. The U.S. owner must check the “Substitute Form 3520-A” box on the attached form. For background on how Form 3520 reports foreign trust transactions and large foreign gifts, see our companion guide.

The IRS Instructions for Form 3520-A provide details on required owner and beneficiary statements.

Where Do You File Form 3520?

Mail Form 3520 separately from your income tax return to:

Internal Revenue Service Center
P.O. Box 409101
Ogden, UT 84409

Only a complete Form 3520 is considered timely filed. A complete filing includes all required schedules, statements, and attachments. A form submitted without necessary documentation may not protect you from late-filing consequences.

What Happens If You Miss the Form 3520 Due Date?

If you are late, the first step is to file a complete Form 3520 promptly, with a reasonable-cause statement and supporting documents. Reasonable cause means circumstances showing that the failure resulted from reasonable cause and not willful neglect.

If the IRS catches the problem and issues a CP15 notice, that notice triggers the penalty assessment. Penalties can be significant. Under section 6677, the initial penalty may be the greater of $10,000 or 35% of the gross value transferred to, or distributed from, a foreign trust. A Form 3520-A failure may involve 5% of the relevant trust assets, and certain foreign-gift reporting failures may result in a penalty of 5% per month, up to 25%. See how Form 3520 and 3520-A penalties are calculated and the IRS penalty handbook for international information returns.

Foreign-country disclosure penalties, trustee reluctance, or trust provisions restricting disclosure generally are not reasonable cause. A complete late filing and supported explanation can provide a practical path forward. See the penalty appeal and abatement process. If you need help determining when to file Form 3520, responding to an IRS notice, or preparing a penalty-abatement request, contact the Law Offices of Jason R. Kovan. We can review your situation confidentially and explain next steps, protected by attorney-client privilege once an engagement letter is signed. You can also review why the IRS changed how Form 3520 penalties are assessed in 2026.