A foreign trust, for US tax purposes, is any trust that fails either of two tests set out in federal regulations: a US court must have primary supervision over the trust’s administration, and US persons must control all substantial decisions. Fail either one and the trust is foreign, no matter where the assets sit, where the trustee lives, or what the trust document calls itself. That label matters because it pulls the trust and every US person connected to it into a separate tax and reporting regime, one with penalties that routinely reach 35% of unreported amounts and distribution rules that can push effective tax rates past 50%.
The Two-Part Test That Defines a Foreign Trust
Federal regulations set two requirements a trust must satisfy at the same time to count as domestic. Miss either, and the IRS treats the trust as foreign by default.1eCFR. 26 CFR 301.7701-7 – Trusts Domestic and Foreign
The Court Test
The court test asks whether a US court can exercise primary supervision over the trust’s administration. Primary supervision means authority to resolve substantially all issues about how the trust operates. A trust administered entirely in the United States under an instrument that does not direct administration abroad generally satisfies this test. The common trap is a “flee clause,” a provision that automatically shifts the trust’s jurisdiction outside the US if a court tries to assert authority. A trust with an automatic migration provision fails the court test, even if it has been administered domestically for years.1eCFR. 26 CFR 301.7701-7 – Trusts Domestic and Foreign
The Control Test
The control test asks whether one or more US persons hold authority over all substantial decisions of the trust. Substantial decisions include whether and when to make distributions, how to invest trust assets, whether to appoint or remove trustees, and whether to terminate the trust. Every one of these must rest with US persons. If a non-US person holds a veto or shares authority over even a single substantial decision, the trust fails this test.1eCFR. 26 CFR 301.7701-7 – Trusts Domestic and Foreign
The burden runs one direction: the IRS treats a trust as foreign unless the taxpayer can show it passes both tests. That default catches a surprising number of arrangements, especially trusts set up in common-law jurisdictions like the Channel Islands, Cayman Islands, or New Zealand that may have a US grantor but a non-US trustee making investment decisions.
Who Counts as a US Person
Because both tests hinge on “US persons,” the definition is doing real work. A US person includes any US citizen or resident, any domestic partnership or corporation, any non-foreign estate, and any trust that itself qualifies as domestic under the two-part test.2Internal Revenue Service. Classification of Taxpayers for US Tax Purposes Green card holders and individuals who meet the substantial presence test are US persons too, even when they maintain primary residences abroad. That sweeps in dual citizens and long-term residents who may not think of themselves as US taxpayers but are, absolutely, for foreign trust purposes.
Who Pays the Tax: Grantor vs. Non-Grantor
Once a trust is foreign, the next question is who the IRS taxes. The answer depends on whether the trust is a grantor trust or a non-grantor trust. The split controls whether tax lands on the person who funded the trust or on the people who receive distributions.
Foreign Grantor Trusts
A foreign grantor trust is one where a US person is treated as owning the trust’s assets for income tax purposes. The most common trigger is Section 679: if a US person transfers property to a foreign trust and that trust has or could have a US beneficiary, the transferor is treated as the trust’s owner.3Office of the Law Revision Counsel. 26 USC 679 – Foreign Trusts Having One or More United States Beneficiaries “US beneficiary” is read broadly and includes anyone who might receive distributions in the future, not just current recipients.
As deemed owner, the US grantor reports the trust’s worldwide income, deductions, and credits directly on their own return, as though they personally earned or paid every item.4Internal Revenue Service. Foreign Grantor Trust Determinations The trust is essentially transparent for income tax purposes. That applies even if the trust sits in a zero-tax jurisdiction and the grantor never sees a dollar of the income.
Foreign Non-Grantor Trusts
When the grantor trust rules do not apply, the foreign trust is treated as a separate entity taxed like a nonresident alien. The trust itself owes US tax only on income from US sources or income connected to a US business. Everything else escapes US tax at the trust level.
That sounds like a benefit. The trade-off hits when distributions flow to US beneficiaries, because the accumulated income that was not taxed at the trust level gets taxed to the beneficiary under rules designed to wipe out the deferral advantage. Those are the throwback rules, and they routinely produce bills higher than what the beneficiary would have owed if the income had been distributed and taxed each year as earned.
The Tax Hit When You Transfer Property In
Before annual income tax even enters the picture, a US person who transfers appreciated property to a foreign trust faces an immediate tax. The transfer is treated as a sale at fair market value, and the transferor must recognize the gain as though they sold the property on the open market.5Office of the Law Revision Counsel. 26 USC 684 – Recognition of Gain on Certain Transfers to Certain Foreign Trusts and Estates The rule stops US persons from shifting built-in gains into foreign structures where those gains might never be taxed.
Three situations are exempt from this forced gain recognition.6eCFR. 26 CFR 1.684-3 – Exceptions to General Rule of Gain Recognition The first is a transfer to a trust the transferor is already treated as owning under the grantor trust rules: there is no deferral to prevent, because the transferor is already taxed on all the income. The second covers transfers to foreign trusts that qualify as tax-exempt charitable organizations. The third applies at death, when property passes to a foreign trust and the recipient takes a stepped-up basis.
The grantor-trust exception matters most in practice. Many transfers to foreign trusts are structured so Section 679 grantor trust treatment applies first, avoiding the upfront gain. If grantor trust status later lapses, the trust’s assets may trigger gain recognition at that point.
How Distributions From Foreign Non-Grantor Trusts Are Taxed
Taxation of distributions from a foreign non-grantor trust is where the complexity spikes. Unlike a domestic trust, where distributions generally carry out current-year income to beneficiaries in a fairly direct way, foreign trust distributions run through a separate calculation built to recapture years of untaxed accumulation.
Current-Year Income vs. Accumulated Income
Each distribution is split into two buckets. The portion coming out of the trust’s distributable net income for the current year is taxed to the beneficiary at ordinary rates for that year. Any amount beyond the current year’s income is treated as an accumulation distribution, representing income the trust earned and retained in prior years.7Office of the Law Revision Counsel. 26 USC 665 – Definitions Applicable to Subpart D
The Throwback Rules and Interest Charge
Accumulation distributions trigger the throwback rules. The IRS allocates the accumulated income back to the earlier years when the trust earned it, computes what additional tax the beneficiary would have owed had the income been distributed and reported each year as earned, and then adds a non-deductible interest charge computed at the underpayment rate for the entire deferral period.8GovInfo. 26 USC 668 – Interest Charge on Accumulation Distributions From Foreign Trusts
The interest charge is the real sting. It compounds over the entire accumulation period and cannot be deducted against any tax. For trusts that have accumulated income over a decade or more, the interest alone can rival or exceed the underlying tax, and the combined effect often pushes the effective rate above 50%. That is the design: Congress wanted to eliminate any benefit from parking income in a low-tax foreign trust.
Capital gains accumulated inside a foreign non-grantor trust also lose their favorable character when distributed. Instead of long-term capital gains rates, they fold into the accumulation distribution calculation and are effectively taxed as ordinary income. That is one of the nastier surprises for beneficiaries who assumed investment gains would retain their character.
Loans Treated as Distributions
A loan of cash or marketable securities from a foreign trust to a US grantor, beneficiary, or anyone related to them is treated as a taxable distribution for the full loan amount. Repayment does not undo the tax: the statute says any later transaction between the trust and borrower regarding the loan principal is disregarded.9Office of the Law Revision Counsel. 26 USC 643 – Definitions Applicable to Subparts A, B, C, and D
The only escape is structuring the loan as a “qualified obligation.” Under proposed regulations, that requires a written loan with a term no longer than five years, all payments in US dollars, an interest rate between 100% and 130% of the applicable federal rate, annual reporting of the loan status on Form 3520, and an extension of the assessment period for any related tax.10Federal Register. Transactions With Foreign Trusts and Information Reporting on Transactions With Foreign Trusts and Large Foreign Gifts Miss any one of these and the full loan is taxed as a distribution.
What You Have to File
US persons connected to foreign trusts face several reporting obligations, each with its own deadline and its own penalty. The mechanics are where people most often get hurt.
Form 3520
Form 3520 is the return for reporting transactions with foreign trusts and receiving foreign gifts. A US person must file it if they transfer property to a foreign trust, receive a distribution from one, or are treated as an owner of any part of one. It is due on the same date as your income tax return, including extensions, which is April 15 for most calendar-year taxpayers or October 15 with an extension.11Internal Revenue Service. Reminder to US Owners of a Foreign Trust
Form 3520-A
Form 3520-A is the annual information return the foreign trust itself must file if it has a US owner. It gives the detailed accounting the US owner needs for their own return: the trust’s income, expenses, and the US owner’s share of each. It is due the 15th day of the third month after the trust’s tax year ends, which is March 15 for calendar-year trusts. A six-month extension is available on Form 7004, but an extension on your personal income tax return does not extend the Form 3520-A deadline.12Internal Revenue Service. Instructions for Form 3520-A
The foreign trustee is primarily responsible for filing, but if the trustee does not, the US owner must submit a substitute Form 3520-A attached to their Form 3520 to avoid being penalized for the trustee’s failure.12Internal Revenue Service. Instructions for Form 3520-A Getting foreign trustees to cooperate with US filing obligations is one of the persistent practical headaches of foreign trust ownership. Many offshore trustees are unfamiliar with or indifferent to US reporting rules, which leaves the US owner holding the bag.
FBAR
If a foreign trust holds financial accounts outside the US and a US person has a financial interest in or authority over those accounts, the US person must file an FBAR (FinCEN Form 114) whenever the aggregate value of all foreign accounts exceeds $10,000 at any point during the calendar year. A US person treated as the owner of a foreign grantor trust generally has a financial interest in the trust’s accounts for FBAR purposes. Beneficiaries do not have to file if a US person such as the trustee or an agent already files an FBAR covering those accounts.13Internal Revenue Service. Report of Foreign Bank and Financial Accounts (FBAR)
Form 8938
Interests in foreign trusts are “specified foreign financial assets” that may require reporting on Form 8938 under FATCA. Thresholds vary by filing status and whether you live in the US or abroad, starting at $50,000 at year-end or $75,000 at any time during the year for a single filer living in the US, and climbing to $400,000 at year-end or $600,000 at any time for joint filers living abroad.14Internal Revenue Service. Do I Need to File Form 8938, Statement of Specified Foreign Financial Assets Form 8938 is filed with your income tax return. It overlaps with the FBAR but serves a different enforcement purpose and uses different thresholds. You may need to file both for the same accounts.
What You Need to Compile
Both Form 3520 and Form 3520-A require detailed data: the identities and addresses of all trustees, settlors, and beneficiaries; the trust’s income statement and balance sheet; a breakdown of transfers in and out during the year; and the maximum value of trust assets at year-end. US beneficiaries need records showing the amount and date of each distribution along with its classification as current-year income, accumulated income, or return of principal. Without that classification, the entire distribution is presumed to be an accumulation distribution and automatically subject to the throwback rules and interest charge.
Penalties and How to Fix a Late Filing
The penalties here are designed to hurt, and they are assessed automatically. The IRS does not need to prove you owed additional tax or acted in bad faith to impose them.
For failure to file Form 3520 reporting a distribution from a foreign trust, the penalty is the greater of $10,000 or 35% of the gross reportable amount. For failures related to Form 3520-A, the penalty is the greater of $10,000 or 5% of the gross value of the trust assets treated as owned by the US person. If the failure continues after the IRS mails a notice, an additional $10,000 penalty accrues for each 30-day period the failure persists beyond 90 days from the notice date. Aggregate penalties are capped at the gross reportable amount, but reaching that cap is cold comfort when the reportable amount is substantial.15Office of the Law Revision Counsel. 26 USC 6677 – Failure to File Information With Respect to Certain Foreign Trusts
These penalties apply whether or not the distribution was taxable. A return-of-principal distribution that carries zero tax liability still triggers the 35% penalty if unreported. That catches people off guard more than almost anything else in this area.
No penalty applies if the failure is due to reasonable cause and not willful neglect, but the IRS reads reasonable cause narrowly here. A written statement explaining the failure is required, and it must include a declaration under penalties of perjury. The fact that a foreign country would impose civil or criminal penalties for disclosing the required information is explicitly not reasonable cause. The IRS also evaluates reasonable cause for the initial penalty and any continuation penalties separately, so a taxpayer who had a legitimate reason for the original failure but then ignored the IRS notice will have a harder time with the continuation penalties.16Internal Revenue Service. Failure to File the Form 3520/3520-A – Penalties
If you discover past filing failures before the IRS contacts you, the IRS maintains delinquent international information return submission procedures that allow late filings with a reasonable cause statement. In more complex situations involving unreported foreign income, the streamlined filing compliance procedures may apply, though those carry their own requirements and potential penalties.17Internal Revenue Service. Streamlined Filing Compliance Procedures for US Taxpayers Residing in the United States Coming forward voluntarily before the IRS finds you is almost always the better path. Once an examination opens, the leverage to negotiate penalty relief drops sharply.