Foreign Situs Trust: Taxation, Reporting Forms, and Penalties

Taxation of a foreign situs trust depends entirely on how the trust is classified. If it’s a foreign grantor trust, the U.S. grantor reports and pays tax on all of the trust’s worldwide income as if they earned it directly. If it’s a foreign non-grantor trust, only U.S.-source income is taxed at the trust level, but distributions of accumulated income to U.S. beneficiaries trigger the throwback rules, a nondeductible interest charge, and loss of preferential capital gains rates. On top of the income tax itself, missing the required information returns can cost the greater of $10,000 or 35% of the amount involved.¹

What Makes a Trust “Foreign”

A trust is domestic only if it passes two tests at the same time; fail either and the IRS treats it as foreign.² The court test requires that a U.S. court be able to exercise primary supervision over the trust’s administration. The control test requires that one or more U.S. persons have authority over all substantial decisions of the trust, meaning who receives distributions, how much, and whether beneficiaries can be added or removed. If a foreign co-trustee holds a veto over even one of those decisions, the control test fails and the trust is foreign.³

The burden is on the taxpayer to show both tests are met. Everything that follows in this article assumes the trust is foreign.

Foreign Grantor Trusts: Who Pays Tax and on What

When a foreign trust is a grantor trust, its separate identity disappears for income tax purposes. The grantor reports every dollar of the trust’s income, deductions, and credits on their personal return.⁴ The tax reaches worldwide income, not just U.S.-source income, and applies whether or not the trust actually distributed anything to anyone.

The advantage is a clean structure: no entity-level tax, no throwback rules, no interest charges. Distributions to U.S. beneficiaries are generally not taxed again because the grantor has already paid the tax. The disadvantage is that the grantor bears the full U.S. tax bill on income they may never see, including amounts reinvested or accumulated offshore.

Section 679 Turns Many Foreign Trusts Into Grantor Trusts Automatically

This is the rule that catches people off guard. If a U.S. person transfers property to a foreign trust and the trust has even one U.S. beneficiary — including contingent or future beneficiaries — the transferor is automatically treated as the trust’s owner for income tax purposes.⁵ The grantor’s loss of legal control doesn’t matter. A trustee in Zurich and a governing law of Switzerland don’t matter. If a U.S. beneficiary appears anywhere in the instrument, the IRS looks through the structure and taxes the grantor.

Two narrow exceptions apply: transfers by reason of the transferor’s death, and transfers for which the transferor received fair market value. The fair market value exception is itself narrowed, because obligations from the trust, from any beneficiary, or from anyone related to those parties generally do not count as valid consideration.

A separate trap catches foreign nationals who move to the United States. A nonresident alien who transfers property to a foreign trust and then establishes U.S. residency within five years is treated, retroactively, as if the transfer happened on the residency start date, along with the full set of grantor trust obligations that come with it.

Foreign Non-Grantor Trusts: Tax at the Trust and the Beneficiary

A foreign trust that isn’t a grantor trust is treated as a separate taxpayer, roughly like a nonresident alien.⁶ At the trust level, only U.S.-connected income is taxed: U.S. dividends, U.S. rental income, income effectively connected with a U.S. trade or business, and gains from selling U.S. real property. Foreign-source income sitting in the trust escapes U.S. tax while it stays there.

That deferral largely disappears once the money reaches a U.S. beneficiary.

Throwback Rules, Ordinary-Income Treatment, and Interest

When a foreign non-grantor trust distributes income it earned and accumulated in prior years, the throwback rules retroactively tax that income to the beneficiary as if it had been distributed in the year the trust originally earned it. These rules apply only to foreign trusts; domestic trusts created after 1984 are exempt.⁷

Three consequences make this brutal. The accumulated income is taxed at the beneficiary’s highest marginal rate for the years in which the trust earned it. Capital gains lose their preferential rate and are taxed as ordinary income, which stings when the trust has been sitting on investment gains for years. And the IRS adds a nondeductible interest charge, calculated at the underpayment rate, to compensate for the years of deferral.⁸

Distributions follow a strict ordering rule. Current-year distributable net income comes first, then prior years’ accumulated income starting with the oldest year, and only after all accumulated income is exhausted does anything count as tax-free return of principal. For a trust that has been accumulating for a decade or more, the combined tax and interest can consume a startling share of what the beneficiary receives.

Loans and Free Use of Trust Property Count as Distributions

Borrowing from the trust or living in a trust-owned house rent-free is not a workaround. Under Section 643(i), a loan of cash or marketable securities from a foreign trust to a U.S. grantor, U.S. beneficiary, or a person related to either is treated as an outright distribution equal to the loan amount.⁹ Repaying the loan later does not undo the tax; the IRS ignores the repayment.

Uncompensated use of trust property gets the same treatment. If a U.S. beneficiary uses a trust-owned apartment, car, or artwork without paying fair market rent, the fair market value of that use is treated as a taxable distribution unless the trust receives fair market payment within a reasonable period. Any deemed distribution under these rules also triggers a Form 3520 filing for that year.

Tax When You Fund the Trust

Funding a foreign non-grantor trust with appreciated property is treated as a sale at fair market value. The transferor owes capital gains tax on the full built-in gain even though nothing was actually sold.¹⁰ Stock bought for $100,000 and transferred at $500,000 produces an immediate $400,000 gain on the transferor’s return.

This deemed-sale rule does not apply to transfers into a foreign grantor trust, since the grantor is already treated as the trust’s owner. The exposure reappears if the trust later loses grantor trust status, for example when the last U.S. beneficiary renounces their interest; the trust effectively converts to a non-grantor trust and the deemed-sale rule can bite at that point.

Funding a foreign trust can also be a completed gift for federal gift tax purposes. A transfer to an irrevocable trust where the grantor keeps no power to revoke or redirect the assets is generally a completed gift, reportable on a gift tax return, though the annual exclusion and lifetime exemption apply.

Estate Tax and the Basis Step-Up Problem

Whether the trust ends up in the grantor’s gross estate at death depends on what powers or interests the grantor retained. If the grantor kept the right to income from the assets, or the power to decide who receives them, the value is pulled into the gross estate.¹¹ The same result follows from a retained power to change, revoke, or terminate the trust.¹²

Estate inclusion carries a silver lining: assets in the gross estate generally receive a stepped-up basis to fair market value at the date of death, wiping out unrealized capital gains for the heirs. Many foreign trusts are designed to sit outside the estate, and IRS Revenue Ruling 2023-2 confirmed the consequence — assets in an irrevocable grantor trust that are not included in the gross estate do not get a step-up.¹³ Beneficiaries inherit the grantor’s original cost basis and the full built-up gain remains taxable.

Planning around this involves a real trade-off. Keeping assets out of the estate saves estate tax and forfeits the step-up. Bringing them into the estate secures the step-up and creates estate tax exposure. The right choice depends on the size of the estate, the amount of appreciation, and how much of the exposure the applicable estate tax exemption absorbs.

Reporting Forms You Have to File

U.S. persons connected to a foreign trust face several overlapping information returns, designed so that if one filing is missed, another can still surface the arrangement.¹⁴

Form 3520

Form 3520 is the primary return. U.S. grantors file it to report the creation of a foreign trust and any transfers to it; U.S. beneficiaries file it to report distributions received; U.S. owners of foreign grantor trusts file it to report their ownership.¹⁵ It’s due on the 15th day of the fourth month after year-end, so April 15 for calendar-year filers, with an automatic extension to June 15 for taxpayers living and working abroad. A general extension of the income tax return extends Form 3520 as well.⁹

Form 3520-A

Form 3520-A is the annual information return the foreign grantor trust itself must file, reporting income, assets, and distributions to U.S. owners and beneficiaries. Responsibility falls on the foreign trustee, and it’s due by the 15th day of the third month after the trust’s year-end (March 15 for calendar-year trusts).¹⁶

Foreign trustees frequently refuse to file or don’t realize they must. When that happens, the U.S. owner has to prepare and attach a substitute Form 3520-A to their own Form 3520 to avoid taking the penalty for the trustee’s failure.

FBAR

If a foreign trust holds financial accounts abroad with an aggregate value over $10,000 at any point in the year, an FBAR must be filed. It goes to FinCEN electronically through the BSA E-Filing system, not to the IRS with the tax return, and is due April 15 with an automatic extension to October 15.¹⁷

Form 8938

Form 8938 is the FATCA disclosure of specified foreign financial assets, which can include an interest in a foreign trust. Thresholds depend on filing status and residence. For a single filer in the United States, the trigger is $50,000 at year-end or $75,000 at any point during the year. For married couples filing jointly in the United States, those thresholds double to $100,000 and $150,000. Taxpayers living abroad get higher thresholds: $200,000 year-end or $300,000 anytime for single filers, and $400,000 or $600,000 for joint filers.¹⁸ Unlike the FBAR, Form 8938 attaches to your income tax return.

Penalties for Missing a Filing

The penalty structure is meant to make noncompliance more expensive than any tax benefit the trust might offer. For Form 3520, the initial penalty is the greater of $10,000 or a percentage of the amount involved:⁹

35% of the gross value of property transferred to the trust.
35% of the gross value of distributions received from the trust.
5% of the gross value of trust assets treated as owned by the U.S. person, where Form 3520-A is missed.

If the failure continues after the IRS sends a notice, a continuation penalty of $10,000 per 30-day period stacks on top, capped at the total gross reportable amount.¹ On a $1 million distribution, the initial penalty alone runs $350,000.

FBAR penalties are separate. A non-willful violation can cost up to $10,000 per violation, adjusted for inflation. A willful violation runs to the greater of $100,000 or 50% of the highest account balance during the year, per violation.

A reasonable cause defense can waive Form 3520 and Form 3520-A penalties if the taxpayer shows in writing, signed under penalties of perjury, that the failure was not due to willful neglect.¹⁹ A foreign country’s own rule against disclosing the information does not qualify. The IRS evaluates the initial penalty and the continuation penalty separately, so a valid excuse for the original miss doesn’t insulate you from continuation penalties if you don’t act quickly after the notice arrives.

1
Office of the Law Revision Counsel. 26 U.S. Code 6677 – Failure to File Information With Respect to Certain Foreign Trusts
2
Office of the Law Revision Counsel. 26 USC 7701 – Definitions
3
eCFR. 26 CFR 301.7701-7 – Trusts Domestic and Foreign
4
Office of the Law Revision Counsel. 26 U.S. Code 671 – Trust Income, Deductions, and Credits Attributable to Grantors and Others as Substantial Owners
5
Office of the Law Revision Counsel. 26 USC 679 – Foreign Trusts Having One or More United States Beneficiaries
6
Internal Revenue Service. Taxation of Beneficiary of a Foreign Non-Grantor Trust
7
Office of the Law Revision Counsel. 26 U.S. Code 665 – Definitions Applicable to Subpart D
8
U.S. Government Publishing Office. 26 USC 668 – Interest Charge on Accumulation Distributions From Foreign Trusts
9
Internal Revenue Service. Instructions for Form 3520
10
Office of the Law Revision Counsel. 26 U.S. Code 684 – Recognition of Gain on Certain Transfers to Certain Foreign Trusts and Estates
11
Office of the Law Revision Counsel. 26 U.S. Code 2036 – Transfers With Retained Life Estate
12
Office of the Law Revision Counsel. 26 USC 2038 – Revocable Transfers
13
Internal Revenue Service. Revenue Ruling 2023-2
14
Internal Revenue Service. Foreign Trust Reporting Requirements and Tax Consequences
15
Internal Revenue Service. About Form 3520, Annual Return To Report Transactions With Foreign Trusts and Receipt of Certain Foreign Gifts
16
Internal Revenue Service. Instructions for Form 3520-A – Annual Information Return of Foreign Trust With a U.S. Owner
17
Internal Revenue Service. Report of Foreign Bank and Financial Accounts (FBAR)
18
Internal Revenue Service. Do I Need to File Form 8938, Statement of Specified Foreign Financial Assets
19
Internal Revenue Service. Failure to File the Form 3520/3520-A Penalties