Form 3520: Foreign Trusts, Foreign Gifts, and the $10,000 Section 6677 Penalty

Form 3520 is an annual information return, not a tax return in the sense of calculating what you owe. It is the paper the IRS reads to see whether a U.S. person is on the right side of three cross-border rules at the same time: the foreign trust transfer rules, the grantor-trust ownership rules, and the foreign-gift reporting rule. The IRS states the scope in one sentence: "U.S. persons (and executors of estates of U.S. decedents) file Form 3520 to report: Certain transactions with foreign trusts. Ownership of foreign trusts under the rules of sections Internal Revenue Code 671 through 679. Receipt of certain large gifts or bequests from certain foreign persons."^[1]

That three-part scope is why one person can trigger the form in a tax year with no money changing hands at all. A U.S. owner of a foreign grantor trust has to file for each tax year the ownership continues, even if nothing was contributed and nothing was distributed. A U.S. beneficiary who received a distribution has to file for the tax year of that distribution. And a resident who received a large gift from a parent abroad has to file for the tax year it arrived. The three triggers run on their own clocks, so the question is never whether a filing happened before, but which of the three happened within the tax year at hand. For the broader framework of cross-border information returns a Miami household should expect, see the forms and penalties framework for a foreign-owned U.S. business.

A U.S. person for Form 3520 is a U.S. citizen, a lawful permanent resident (green card holder), a resident alien who meets the substantial presence test, and a U.S. domestic trust, estate, partnership, or corporation. Immigration status is not the test on its own: a Latin American client who lived in the United States long enough to meet the substantial presence test is a U.S. person for this form, and the Mexican or Colombian family trust that previously stayed invisible to the IRS can land in scope the moment that threshold is crossed.

Two features of the form widen that circle further. First, a U.S. person who is treated as the owner of a foreign trust under the grantor trust rules of sections 671 through 679 has to file whether or not anything moved during the tax year, and whether or not the person set the trust up. Second, a U.S. recipient of a distribution has to report it even when the distribution came through someone else, because the IRS defines a distribution to include indirect transfers from a trust. For the return that carries the related income reporting, see individual tax return preparation.

The IRS splits the universe in two with a short, mechanical test: "A foreign trust is any trust other than a domestic trust. A domestic trust is any trust if: A court within the United States is able to exercise primary supervision over the administration of the trust, and One or more U.S. persons have the authority to control all substantial decisions of the trust."^[9] Fail either prong of the domestic test, and the trust is foreign for every purpose in this form.

That two-prong test is where real money gets lost. A trust set up in Mexico, Colombia, Venezuela, or the Bahamas with a local court supervising it, or with a non-U.S. trustee holding substantial decisions, is foreign even when the only beneficiary lives in Miami. A trust that was domestic when it was created can migrate to foreign the day the last U.S. co-trustee resigns, because the all substantial decisions prong goes with the trustee. The classification is almost never obvious from the deed alone, which is why a client with foreign family trust exposure usually needs advisory solutions before the return season starts rather than after a notice arrives.

The gift reporting rule is on a different page of the form, Part IV, and runs on a different threshold from everything else. The IRS states who it reaches: a U.S. person who "received either: More than $100,000 from a nonresident alien individual or a foreign estate (including foreign persons related to that nonresident alien individual or foreign estate) that you treated as gifts or bequests; or More than the section 6039F threshold amount from foreign corporations or foreign partnerships (including foreign persons related to such foreign corporations or foreign partnerships) that you treated as gifts."^[4]

Two features of the threshold catch people out. The $100,000 figure applies to the aggregate for the year, not to each individual gift, and the rule pulls in related persons on the giver side, so several smaller transfers from a parent and a sibling abroad are counted together. And the Part IV threshold is a reporting threshold, not a tax threshold. The gift itself is generally not U.S. taxable to the recipient, which is why many clients assume no filing is required and then learn otherwise when the first penalty notice arrives. For readers who also hold the foreign bank account the gift arrived into, how FBAR and Form 8938 reach the same foreign account covers the FBAR side of the same facts.

Section 6677 is where a missed Form 3520 moves from expensive to ruinous for a Miami household. The IRS pegs the initial amount at "the greater of $10,000 or" a listed percentage of the amount at stake.^[5] That listed percentage is 35 percent on a missed Part I transfer, 35 percent on a missed Part III distribution, or 5 percent on a missed Part II owner position, measured against the slice of trust assets attributable to the U.S. owner under the grantor trust rules of sections 671 through 679.^[5] The $10,000 floor is why even a dormant Mexican or Colombian family trust with modest assets still carries real exposure if the form is skipped.

A second rule compounds the number as soon as the IRS puts a notice in the mail: "Additional penalties will be imposed if the noncompliance continues for more than 90 days after the IRS mails a notice of failure to comply with the required reporting."^[6] The 90 day clock runs from the date of that IRS notice, not from the original filing deadline, which is why the notice itself is the moment a reader with any Form 3520 exposure needs representation rather than another month of silence. Our IRS representation work covers the response once a notice is in the mailbox.

A missed Part IV reports its own penalty, separate from Section 6677. The IRS states it directly: "In the case of a failure to timely report foreign gifts described in section 6039F, the IRS may determine the income tax consequences of the receipt of such gift, and a penalty equal to 5% of the amount of such foreign gifts applies for each month for which the failure to report continues (not to exceed a total of 25%)."^[7]

Two features of that sentence matter more than its headline rate. The 5 percent runs monthly, so a disclosure a year after the original due date can reach the 25 percent cap by the time the paperwork arrives. And the second clause, the IRS may determine the income tax consequences of the receipt of such gift, is the quiet one. A foreign gift is ordinarily not income, but once reporting lapses the IRS can treat the receipt as income unless the taxpayer can show otherwise, which flips the burden onto the person who missed the filing. That is why an unreported inheritance from Mexico or Colombia almost always costs more to defend than to report on time.

A foreign trust with a U.S. owner has its own return, Form 3520-A, the Annual Information Return of Foreign Trust With a U.S. Owner. The ordinary filer of that return is the foreign trust itself, and in practice a trust held in Mexico, Colombia, or Panama almost never files it on its own. The U.S. owner is then caught by a separate rule: the Section 6677 penalty on the 5 percent of grantor-trust-assets prong reaches the owner, not the trust, when Form 3520-A is late.^[5]

The IRS gives the U.S. owner a self-help route called a substitute Form 3520-A. The deadline rule is explicit: "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."^[11] The practical effect is that the owner who completes a substitute Form 3520-A and attaches it to Form 3520 by the owner's own deadline is treated as having filed the trust's return on time. Letting the foreign trustee promise to file next month instead is the single most common path to the 5 percent penalty.

The core deadline follows the individual income tax calendar. The IRS states: "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."^[2] For a calendar-year individual that is the 15th day of the 4th month, pushed to the 15th day of the 6th month for the taxpayer who lives and works abroad on the April due date.

Filing an income tax extension pulls Form 3520 with it. The IRS states: "If a U.S. person is granted an extension of time to file an income tax return, Form 3520 is due no later than the 15th day of the 10th month following the end of the U.S. person's tax year."^[3] That reaches the same October window the main return has. The hidden rule is that Form 3520 does not carry its own extension form, the extension of the income tax return is what carries it. A filer who extended the main return but mailed Form 3520 separately on the October date is on time. A filer who did not extend the main return and tried to file Form 3520 on the October date is six months late, and the Section 6677 clock has been running the whole time.

A Mexican fideicomiso is the bank-held trust Mexico uses to let a non-Mexican hold title inside the restricted zone, the strip along the Pacific and Caribbean coasts and the northern border. For a Miami client who bought a condominium in Playa del Carmen, Puerto Vallarta, or Tulum, the deed sits in a Mexican bank as trustee, and the client is the beneficiary. Whether that arrangement is a foreign trust for Form 3520 and Form 3520-A purposes is a fact-based classification, decided against the two-prong domestic-trust test above and against the IRS's own guidance on fideicomisos as nominee or title-holding arrangements.^[9]

The safest reading is that a classification call this heavy belongs to representation, not to the client's own judgment. A fideicomiso treated as a nominee or title-holding structure that reports the Mexican property as directly held by the U.S. beneficiary carries one filing posture. A fideicomiso the IRS views as a foreign trust carries Form 3520 and Form 3520-A each year the arrangement persists, plus the Section 6677 exposure if either is missed. The cost of getting the classification wrong is the greater of $10,000 or the stated percentage, which is why the first conversation about any coastal Mexican property deserves professional review before the next return season begins. For readers whose Mexican or Latin American holdings also touch U.S. real estate on the sell side, foreign-owned U.S. entity tax services carries the related entity side of the same work.

The normal statute of limitations on an income tax return assumes the return was actually filed. Form 3520 breaks that assumption for a related U.S. tax return. The IRS states it as follows: "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."^[10]

Read that sentence twice. The 3 year clock does not run from the original tax return filing. It runs from the day the missing Form 3520 is finally filed, which means a trust transfer or distribution that was never reported can be reached by the IRS indefinitely. The practical implication is that a late Form 3520 is still a cleanup worth doing: a late filing finally starts the 3 year assessment clock on everything the form covers, where silence lets it run forever. A separate accuracy penalty under Section 6662(j) can apply if a U.S. owner of a foreign trust has an underpayment attributable to an asset that was required to be reported on Form 3520-A: "If a U.S. owner of a foreign trust is subject to a 20% penalty imposed under section 6662 for an underpayment of tax required to be shown on a return, then such penalty may be increased to 40% under section 6662(j) for any portion of an underpayment that is attributable to any transaction involving any asset with respect to which information was required to be provided on Form 3520-A."^[8]