International Tax Planning for Ultra-High-Net-Worth Families

Not tax or legal advice. Cross-border tax law is highly fact-specific — work with qualified international tax counsel before acting.

Most UHNW planning guides treat "tax planning" as a domestic question. But a large and growing segment of $30M+ families have international complexity: foreign investment accounts, overseas real estate, foreign trusts, multinational businesses, dual citizenship, or a family history that spans borders. For them, the tax compliance and planning landscape is qualitatively different — and the cost of getting it wrong can be measured in millions.

The US taxes its citizens and permanent residents on worldwide income regardless of where they live or where assets are held. That rule, combined with an aggressive foreign asset reporting regime, means UHNW families with any international footprint need proactive planning, not just compliance. This guide covers the major frameworks: FBAR, FATCA, PFIC, foreign trust reporting, pre-immigration planning, and the Section 877A exit tax.

FBAR: Foreign Bank Account Reporting (FinCEN 114)

Any US person — citizen, resident alien, or certain entity — must file FinCEN Form 114 (the FBAR) if the aggregate value of all foreign financial accounts exceeded $10,000 at any point during the calendar year.¹ Foreign financial accounts include bank accounts, brokerage accounts, mutual funds, insurance policies with cash value, and certain annuity contracts held at foreign financial institutions.

For a UHNW family with even a single foreign investment account, the threshold is irrelevant — you are always filing. What matters is the penalty structure and the compliance discipline required to file correctly every year.

The 2023 Supreme Court decision in Bittner v. United States clarified that the non-willful penalty is per-report (one per year), not per-account — a significant win for taxpayers with many accounts and a past compliance gap. The penalty structure for willful violations is unchanged and remains severe.

Practical note: The FBAR is filed electronically with FinCEN by April 15 (automatic extension to October 15 available). It is not filed with your federal tax return, though both have the same annual cycle. Keeping both in sync with your international tax counsel is essential.

FATCA: Form 8938 and Specified Foreign Financial Assets

The Foreign Account Tax Compliance Act (FATCA) added a second, overlapping foreign asset reporting requirement: Form 8938, filed with your federal income tax return. Form 8938 covers a broader category — "specified foreign financial assets" — that includes not just accounts but also foreign stocks, partnership interests, debt instruments held outside financial institutions, and interests in foreign entities.²

The filing thresholds differ by residency:

FBAR and Form 8938 are not substitutes. The same foreign account may require both filings. The IRS enforces both independently. Missing one while filing the other does not reduce your exposure.

The penalty for failing to file Form 8938 starts at $10,000 and rises to $50,000 for continued failure after IRS notice. Unlike FBAR, the penalty per Form 8938 (not per-asset), and there's a 40% underpayment penalty on income related to undisclosed assets.

PFIC Rules: The Foreign Fund Tax Trap

A Passive Foreign Investment Company (PFIC) is any foreign corporation where either (a) 75% or more of gross income is passive, or (b) 50% or more of assets produce or are held to produce passive income.³ In practice, this captures most foreign mutual funds, many foreign ETFs, certain foreign holding companies, and foreign hedge funds structured as corporations.

The PFIC rules exist because Congress wanted to prevent US taxpayers from deferring income by holding foreign pooled investment vehicles. The tax treatment under the three available regimes ranges from "suboptimal" to "punitive":

For UHNW investors, the PFIC trap most often surfaces in two scenarios: (1) inherited foreign accounts containing foreign funds, and (2) direct investments in foreign hedge funds or pooled vehicles. The election must be made timely — retroactive relief via PLR (Rev. Proc. 2026-10) is now available in limited circumstances, but it's expensive and uncertain.

Form 8621 (updated December 2025) must be filed for each PFIC in which you are a direct or indirect shareholder. For a portfolio with dozens of foreign funds, this can be a significant compliance burden — one more reason UHNW families with international holdings need specialist international tax counsel, not just a general CPA.

Foreign Trust Reporting: Forms 3520 and 3520-A

Foreign trusts interact with US tax law in two key ways — as a planning vehicle and as a compliance obligation.

Section 679 treats a US person who transfers property to a foreign trust with a US beneficiary as the grantor (owner) of that trust for US income tax purposes.⁴ This prevents using a foreign trust structure to defer US income tax. A foreign trust with no current US beneficiary is not subject to §679, but grantor trust status can attach later if a US beneficiary is added.

Reporting obligations:

• Form 3520: Annual return reporting (a) transfers of property to foreign trusts, (b) receipt of distributions from foreign trusts, and (c) receipt of foreign gifts. The threshold for reporting foreign gifts from non-US individuals is $100,000 aggregate per year; from foreign corporations or partnerships, it's $20,573 (inflation-adjusted for 2026). Penalties start at 35% of the reportable amount.⁵
• Form 3520-A: Annual information return filed by the foreign trust itself (or, if the trust fails to file, by the US grantor). Penalties for late or incomplete filing start at $10,000 per failure.

Foreign trusts established before the US person became a US tax resident may avoid grantor trust treatment under §679 for pre-immigration transfers — but this requires careful planning and documentation. See the pre-immigration section below.

Pre-Immigration Planning for Incoming UHNW Residents

Non-US persons planning to establish US tax residency — whether via green card, substantial presence test, or treaty election — have a narrow window to take actions that become much more expensive or impossible after they become US residents. This is the most time-sensitive international planning scenario at UHNW scale.

What can be done before crossing the residency threshold:

1. Gifting non-US assets to family or trusts. The US gift tax applies to US situs property transferred by any person, and to worldwide transfers by US persons. But a non-US person gifting non-US situs property to a non-US person has no US gift tax exposure. Once you become a US resident, all future gifts are subject to US gift tax.
2. Establishing foreign grantor trusts. A foreign trust established by a non-US person, with non-US property, before becoming a US resident can avoid §679 grantor trust classification for the pre-immigration contribution — potentially allowing tax-deferred or different-basis treatment of future distributions. Structure must be correct; errors after the fact are difficult to fix.
3. Basis step-up under applicable treaties. The US does not generally provide a step-up in basis to FMV for assets held on the date of immigration. Some bilateral tax treaties provide a deemed acquisition rule that effectively gives a step-up. This is highly treaty-specific and requires analysis before immigration.
4. Roth conversion timing. If a non-US person will become a US resident, converting foreign retirement accounts or restructuring investments before residency may result in more favorable treatment than doing so after. The interplay between foreign pension arrangements and US treaty rules can be complex — see IRS Publication 54 and the relevant bilateral treaty.
5. Foreign pension and retirement accounts. US residency does not automatically convert foreign pension rights into US-taxable income, but the timing and character of distributions may be affected by whether you elect treaty benefits. The election to treat a foreign pension as tax-deferred must be made on your first US tax return.

The bottom line on pre-immigration timing: The day you become a US tax resident, your entire worldwide income and estate become subject to US taxation. For a family with $50M in non-US assets, the difference between planning done before and after residency establishment can easily be millions of dollars. This is a one-time window — coordinate with international tax counsel 6–18 months before the expected residency date.

Section 877A Exit Tax: Leaving the US with UHNW Wealth

US citizens who renounce their citizenship, and long-term residents (LTRs — green card holders for 8 of the preceding 15 years) who relinquish their status, may be subject to the Section 877A expatriation tax.⁶

A "covered expatriate" is anyone who meets any of three tests on the expatriation date:

1. Net worth test: Net worth of $2 million or more.
2. Average annual net income tax test: Average annual net income tax liability for the 5 preceding years exceeds the inflation-adjusted threshold (see current IRS Form 8854 instructions for the current year amount).
3. Certification test: Failure to certify 5 years of US tax compliance on Form 8854.

For virtually any UHNW person, the net worth test alone makes them a covered expatriate.

The exit tax mechanics:

• All worldwide assets are deemed sold at FMV on the day before expatriation.
• Gain above a per-person exclusion of $910,000 (for 2026, inflation-indexed) is recognized and taxed in the year of expatriation.
• Most gain is taxed as long-term capital gain; ordinary income assets are taxed as ordinary income.
• Special rules apply to deferred compensation, tax-deferred accounts (IRAs, 401(k)s), and interests in foreign grantor trusts — each has its own treatment rather than the deemed-sale rule.

The exit tax interacts with the federal estate tax in important ways. For a family with $30M–$200M, the question of whether to renounce citizenship is never purely a tax question — legal residence, travel, business ties, and multi-generational plans all factor in. But for founders, executives, or inheritors who have genuinely relocated their lives outside the US, the exit tax analysis is worth doing with quantitative precision before making an irrevocable decision.

Tax Treaty Benefits and Tie-Breaker Provisions

The US has bilateral income tax treaties with more than 60 countries. These treaties can reduce withholding rates on dividends, interest, and royalties; provide exemptions from double taxation; and establish residency tie-breaker rules for individuals who might otherwise be tax residents of two countries simultaneously.

Withholding rate reductions: Treaty rates on dividends paid by US companies to foreign shareholders are commonly reduced from 30% (the statutory withholding rate) to 5–15% for qualifying shareholders. UHNW families with foreign beneficiaries or trusts receiving US-source income may benefit significantly from treaty reduced rates.

Tie-breaker provisions: A person who is a tax resident of both the US and a treaty country under each country's domestic rules can invoke the treaty tie-breaker to be treated as a resident of only one country. The tie-breaker analysis is sequential: permanent home → center of vital interests → habitual abode → nationality. For UHNW families with homes in multiple countries, this analysis is rarely straightforward and should be documented carefully in case of audit.

Treaty elections and Form 8833: To take a treaty position that overrides US statutory rules, you must disclose the treaty position on your return using Form 8833. Common treaty positions that UHNW families use include: taxing foreign pension income in the source country rather than the US, treating a dual-resident individual as a non-resident for US tax purposes, and reducing withholding on interest paid to foreign entities.

Foreign Earned Income Exclusion (FEIE)

The Foreign Earned Income Exclusion allows qualifying US persons living and working abroad to exclude up to $132,900 of foreign earned income from US taxable income for 2026.⁷ To qualify, you must meet either the bona fide residence test (a full calendar year as a bona fide resident of a foreign country) or the physical presence test (330 full days in foreign countries in a 12-month period).

For most UHNW families, the FEIE's direct tax impact is modest — $132,900 of excluded income saves at most ~$50,000 in federal tax at the 37% rate. The more significant planning question is usually the interaction between the FEIE and the full US tax system: the FEIE does not eliminate US tax on passive income (dividends, interest, LTCG), it does not affect self-employment tax, and it phases out the tax benefit of many deductions.

However, for UHNW business owners with legitimate foreign earned income, the FEIE stacks with other international planning and is worth capturing properly — especially when combined with the state tax domicile change strategy for eliminating California or New York tax.

Coordination Failures That Cost UHNW Families the Most

International tax law is an area where coordination failures are disproportionately expensive. The most common and costly ones at UHNW scale:

1. Inheriting foreign accounts without PFIC analysis. A US beneficiary who inherits a portfolio of foreign funds may step into a PFIC compliance obligation with no prior elections in place. The default excess distribution regime applies retroactively to the decedent's holding period — potentially generating a very large, unexpected tax bill on the first distribution.
2. Foreign grantor trust becoming non-grantor post-death. A foreign grantor trust typically becomes a foreign non-grantor trust when the grantor dies. The US beneficiary now receives distributions that may be subject to the throwback rules, which treat undistributed income as if it had been distributed in the year it was earned — with an interest charge for the deferral.
3. Pre-immigration gifting to a foreign trust with later US beneficiaries. A family that sets up a foreign trust before immigration to hold non-US assets, and then adds a US-resident child as a beneficiary, triggers §679 grantor trust treatment. The assets — which were planned to be outside the US tax system — are now taxable annually to the US grantor.
4. Missing Form 3520/3520-A deadlines. These forms have the same extended due date as your income tax return, but many taxpayers and even some CPAs are not aware of Form 3520-A, which is filed by the trust (or the grantor if the trust doesn't file). The penalty — starting at $10,000 — accrues immediately and is often disproportionate to the tax at stake.
5. Triggering PFIC status by converting a foreign operating company to a holding company. When a foreign operating business is restructured into a holding company that holds passive assets, it can inadvertently become a PFIC. Post-exit reorganizations and estate planning restructurings should be reviewed for PFIC risk before execution.
6. Domestic estate planning that ignores foreign situs assets. A will or revocable trust designed for a US family may not effectively transfer foreign real estate or foreign accounts. Many countries require local probate or have forced heirship rules that override US testamentary intent. The UHNW estate plan must account for where each asset sits.

Working with a UHNW International Tax Advisor

International tax planning at UHNW scale requires a team, not a single advisor. The coordination challenge is significant: a US attorney who drafts the domestic estate plan may not know the foreign probate rules; a foreign tax advisor may not know how §679 interacts with the domestic grantor trust; a CPA who files the domestic return may not be tracking Form 8621 PFIC elections.

Fee-only financial advisors who specialize in UHNW don't replace international tax counsel — but they coordinate the whole picture. The advisor role is to:

• Map which specialists are needed (US international tax attorney, foreign counsel by jurisdiction, CPA with PFIC experience, foreign exchange specialist)
• Ensure the investment structure and account architecture is consistent with the tax plan
• Monitor planning windows — especially pre-immigration timing and exit tax analysis
• Integrate the domestic tax strategy (state domicile, charitable planning, estate planning) with the international overlay
• Review the annual compliance calendar (FBAR, Form 8938, Form 8621, Form 3520, Form 8833) to catch gaps before they become penalties

The advisor does not replace specialized counsel — they coordinate it. At $30M+ of international complexity, the coordination function is itself worth significant annual expense to get right.

1. FinCEN, Report of Foreign Bank and Financial Accounts (FBAR) — $10,000 threshold and penalty structure.
2. IRS, About Form 8938, Statement of Specified Foreign Financial Assets — FATCA filing thresholds and penalties.
3. IRS, Instructions for Form 8621 (December 2025) — PFIC reporting, QEF and mark-to-market elections, excess distribution regime.
4. IRC § 679 — US owner of foreign trust; grantor trust treatment for transfers by US persons to foreign trusts with US beneficiaries.
5. IRS, About Form 3520 — Foreign trust transactions and foreign gifts reporting; $100,000 gift threshold.
6. IRS, Expatriation Tax (Section 877A) — covered expatriate tests, exit tax mechanics, $910,000 exclusion for 2026, deferred compensation treatment.
7. IRS, Foreign Earned Income Exclusion 2026: $132,900 (IRS Rev. Proc. 2025-67, inflation-indexed).

Values verified as of May 2026. Cross-border tax law is subject to legislative, regulatory, and treaty changes. Consult a qualified international tax attorney for advice specific to your situation and jurisdiction.