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 one or more US persons must control all of the trust’s substantial decisions. Miss either one and the IRS treats the trust as foreign, regardless of where its assets sit or where the trustee lives. That label matters. It changes who owes tax on the trust’s income, how distributions to US beneficiaries are calculated, and what has to be filed each year. Penalties for missed filings start at the greater of $10,000 or 35% of the unreported amount, and the interest charge on accumulated distributions can push effective tax rates above 50%.
The Two-Part Test That Defines a Foreign Trust
Federal regulations set out two requirements a trust must satisfy at the same time to qualify as domestic. Fail either, and the trust is foreign by default.1eCFR. 26 CFR 301.7701-7 – Trusts Domestic and Foreign
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 US, under a trust instrument that doesn’t direct administration abroad, generally passes. The common trap is a “flee clause,” a provision that automatically moves the trust’s jurisdiction outside the US if a court tries to assert authority. Any trust with an automatic migration provision like this fails the Court Test, even if it was otherwise administered domestically for years.
The Control Test asks whether US persons hold authority over all substantial decisions of the trust. Substantial decisions include whether and when to make distributions, how to invest, whether to appoint or remove trustees, and whether to terminate the trust. Every one of those decisions 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.
The burden runs in one direction. The IRS treats a trust as foreign unless the taxpayer can show it passes both tests. That default catches many arrangements set up in common-law jurisdictions like the Channel Islands, Cayman Islands, or New Zealand, where a US grantor may have funded the trust but a non-US trustee makes investment decisions.
Who Counts as a US Person
Because the framework hinges on US-person involvement, the definition matters. 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 even if they live primarily abroad. Dual citizens and long-term US residents often don’t think of themselves as US taxpayers, but they are for foreign trust purposes.
Grantor or Non-Grantor: Who Actually Pays the Tax
Once a trust is classified as foreign, the next question is who pays the US tax on its income. That depends on whether the trust is treated as a grantor trust or a non-grantor trust.
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 that has or could have a US beneficiary, the transferor is treated as the owner.3Office of the Law Revision Counsel. 26 USC 679 – Foreign Trusts Having One or More United States Beneficiaries The scope of “US beneficiary” is broad and includes anyone who might receive distributions in the future.
As the deemed owner, the US grantor reports the trust’s worldwide income, deductions, and credits directly on their own return, as though they personally earned every item.4Internal Revenue Service. Foreign Grantor Trust Determinations The trust is essentially transparent. This applies even if it sits in a zero-tax jurisdiction and the grantor never receives a dollar.
Foreign Non-Grantor Trusts
When the grantor trust rules don’t apply, the trust is a separate entity taxed like a nonresident alien. The trust itself owes US tax only on income from US sources or income effectively connected to a US business. Other income escapes US tax at the trust level.
That deferral disappears when distributions reach US beneficiaries. Accumulated income that wasn’t taxed at the trust level gets taxed to the beneficiary under a set of rules designed to eliminate the deferral advantage, and those rules routinely produce tax bills higher than what the beneficiary would have owed if the income had been distributed each year as earned.
Transferring Property to a Foreign Trust Triggers Gain
Before you even get to annual income tax, a US person who transfers appreciated property to a foreign trust faces an immediate hit. The transfer is treated as a sale at fair market value, and the transferor must recognize 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 exists to stop US persons from shifting built-in gains into foreign structures.
Three situations are exempt from forced gain recognition:6eCFR. 26 CFR 1.684-3 – Exceptions to General Rule of Gain Recognition
- Transfers to a trust the transferor already owns under the grantor trust rules. All the trust’s income is already taxed to them, so there’s nothing to defer.
- Transfers to a foreign trust that qualifies as a tax-exempt charitable organization.
- Transfers at death, where the recipient gets a stepped-up basis.
The grantor trust exception is the one that matters most in practice. Advisors often structure transfers so Section 679 grantor trust treatment applies first, avoiding the upfront gain. If grantor trust status later lapses, gain recognition can trigger at that point.
How Distributions to US Beneficiaries Are Taxed
Distributions from a foreign non-grantor trust run through a separate calculation designed to recapture years of untaxed accumulation. Each distribution is split into two buckets. The portion that comes out of the trust’s distributable net income for the current year is taxed to the beneficiary at their ordinary rates. Any amount exceeding the current year’s income is 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 the trust earned it, computes what additional tax the beneficiary would have owed had the income been distributed each year, and then adds a non-deductible interest charge computed at the underpayment rate over 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 from 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 effective rate on an accumulation distribution often exceeds 50%.
Capital gains lose their favorable character too. Gains accumulated inside a foreign non-grantor trust don’t come out at long-term capital gains rates; they get folded into the accumulation distribution and effectively taxed as ordinary income. Beneficiaries who assume investment gains retain their character are often unpleasantly surprised.
Loans From the Trust Count as Distributions
A loan of cash or marketable securities from a foreign trust to a US grantor, beneficiary, or a related person is treated as a taxable distribution for the full amount of the loan. Repayment doesn’t undo the tax; the statute disregards any subsequent transaction between the trust and borrower regarding the loan principal.9Office of the Law Revision Counsel. 26 USC 643 – Definitions Applicable to Subparts A, B, C, and D
The escape is a “qualified obligation.” Under proposed regulations, that requires all of the following: the loan must be in writing, the term cannot exceed five years, all payments must be in US dollars, the interest rate must fall between 100% and 130% of the applicable federal rate, and the borrower must report the loan status annually on Form 3520 and extend 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 of those and the full loan is taxed as a distribution.
Reporting: Forms 3520 and 3520-A
Two primary reporting obligations attach to US persons connected to foreign trusts. Each has its own deadline and its own penalty.
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’s due on the same date as your income tax return, including extensions.11Internal Revenue Service. Reminder to US Owners of a Foreign Trust
Form 3520-A is the annual information return the foreign trust itself must file if it has a US owner. It provides the accounting the US owner needs for their own return. The due date is the 15th day of the third month after the trust’s tax year ends, so March 15 for calendar-year trusts. A six-month extension is available through 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 Form 3520-A. When the trustee doesn’t file, the US owner must attach a substitute Form 3520-A to their Form 3520 to avoid being penalized for the trustee’s failure. Getting offshore trustees to cooperate with US filings is a persistent practical problem, and the US owner is the one who pays if it goes wrong.
Both forms require the identities and addresses of trustees, settlors, and beneficiaries; the trust’s income statement and balance sheet; a breakdown of all transfers in and out; and the maximum year-end value of the trust’s assets. Beneficiaries need records showing the amount, date, and classification of each distribution as current-year income, accumulated income, or return of principal. Without that classification, the entire distribution is presumed to be an accumulation distribution subject to the throwback rules and interest charge.
FBAR and FATCA May Also Apply
Two additional filings may attach depending on the trust’s financial accounts and total assets.
The FBAR (FinCEN Form 114) is required whenever the aggregate value of foreign financial accounts a US person has an interest in or signature authority over exceeds $10,000 at any point during the calendar year. A US person treated as the owner of a foreign grantor trust typically has a financial interest in the trust’s accounts. Beneficiaries generally don’t have to file separately if a US person such as the trustee or an agent of the trust already files reporting those accounts.13Internal Revenue Service. Report of Foreign Bank and Financial Accounts (FBAR)
Form 8938 under FATCA covers specified foreign financial assets, including interests in foreign trusts. Thresholds depend on filing status and residence:14Internal Revenue Service. Do I Need to File Form 8938, Statement of Specified Foreign Financial Assets
- Single filers in the US: over $50,000 year-end or $75,000 at any time.
- Joint filers in the US: over $100,000 year-end or $150,000 at any time.
- Single filers abroad: over $200,000 year-end or $300,000 at any time.
- Joint filers abroad: over $400,000 year-end or $600,000 at any time.
Form 8938 goes with your income tax return. It overlaps with the FBAR but has different thresholds and a different enforcement purpose, and you may need both for the same accounts.
Penalties for Missing These Filings
The penalties are automatic. The IRS does not have to prove you owed additional tax or acted in bad faith.
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, it’s the greater of $10,000 or 5% of the gross value of the trust assets treated as owned by the US person.15Office of the Law Revision Counsel. 26 USC 6677 – Failure to File Information With Respect to Certain Foreign Trusts
If the failure continues after the IRS mails a notice, an additional $10,000 accrues for each 30-day period beyond 90 days from the notice date. The statute caps aggregate penalties at the gross reportable amount, though that cap offers little comfort when the reportable amount is large.
These penalties apply regardless of whether the distribution was actually taxable. A return-of-principal distribution that produces zero tax liability still triggers the 35% penalty if unreported. That catches people off guard more than almost anything else in this area.
Reasonable Cause and Late-Filing Options
The statute waives the penalty if the failure is due to reasonable cause and not willful neglect. The IRS reads that narrowly. A written statement, signed under penalties of perjury, is required. The fact that a foreign country would impose civil or criminal penalties for disclosing the required information is explicitly not reasonable cause.16Internal Revenue Service. Failure to File the Form 3520/3520-A – Penalties
The IRS evaluates the initial penalty and any continuation penalties separately. A taxpayer with a legitimate reason for the original miss who then ignored the IRS notice for months will have a harder time defending the continuation penalties. What you did after learning of the problem matters as much as why you missed the deadline in the first place.
If you discover past failures before the IRS contacts you, the delinquent international information return submission procedures allow late filings with a reasonable cause statement. Where unreported foreign income is also involved, the streamlined filing compliance procedures may apply, though they carry their own requirements and potential penalties.17Internal Revenue Service. Streamlined Filing Compliance Procedures for US Taxpayers Residing in the United States Coming forward before the IRS finds you is almost always the better path. Once an examination is open, the room to negotiate penalty relief shrinks quickly.