Does this apply if my broker is outside the US?

Yes. Situs follows the asset, not the account. A US-listed ETF held anywhere in the world is US-situs.

What about US stocks I hold directly?

Same treatment: US corporate shares are US-situs.

Is this actually enforced?

Brokers generally require a transfer certificate or equivalent before releasing US-situs assets to heirs, which is the practical enforcement mechanism. It is not a theoretical risk.

Does a joint account solve it?

Not reliably, and joint ownership rules for non-resident aliens differ from the assumptions many investors carry from their own jurisdictions. This is a case for professional advice.

Should I sell my US-listed ETFs today?

Check your own capital gains position first: in a jurisdiction with capital gains tax, the switching cost may argue for transitioning gradually or directing new contributions to Irish funds instead. The direction of travel is clear; the timing is a personal calculation.

Is Luxembourg as good as Ireland here?

For estate-tax situs, both work. For dividend withholding, Ireland's US treaty rate makes it substantially better (Chapter 50).

The US Estate Tax Trap for Non-US Investors

Regional differences

⚠This chapter describes how a tax system works. It is not advice, and estate planning is one area where professional help is genuinely warranted.

How the rule works

US-situs assets for estate-tax purposes include shares of US corporations, US-domiciled funds and ETFs, and certain other US property: regardless of where the investor lives, where the brokerage account is held, or what currency the assets are denominated in. A US-listed ETF held through a Singaporean broker by a Malaysian resident is still US-situs property.

The exemption for non-resident aliens is $60,000 of US-situs assets, in stark contrast to the multi-million exemption available to US citizens and residents. Above it, graduated rates apply, reaching high levels quickly.

The estate must file. Form 706-NA is required, and brokers generally will not release US-situs assets to heirs without a transfer certificate or evidence that estate-tax obligations have been addressed. In practice this means delay, professional fees and a process conducted in a foreign tax system during bereavement.

Treaty relief exists: for some. The US has estate-tax treaties with a limited set of countries, and their terms vary. Most Asian and Middle Eastern jurisdictions, including Singapore, Hong Kong, Taiwan, Malaysia and the UAE, have no US estate-tax treaty. Several European countries do, as do a handful of others, but the coverage is narrow and the details matter.

The same market exposure. Very different estates. The exposure was created by a listing choice and is removed by a listing choice.

What is and is not US-situs

The distinctions are specific enough to be worth listing:

Generally US-situs (exposed):

Shares of US corporations, including US-listed ETFs and US mutual funds: regardless of where held.
Real property located in the US.
Tangible personal property in the US.

Generally not US-situs (not exposed):

Irish and Luxembourg UCITS funds, even when they hold US stocks. The fund is the shareholder of the US companies; you own an Irish security.
US bank deposits (subject to conditions).
Certain US debt obligations qualifying for the portfolio-interest exemption.
Shares of non-US corporations.

The crucial insight in that list: an Irish UCITS fund holding 100% US equities gives you the same market exposure with none of the estate-tax situs. The economic substance is identical; the legal situs is not. This is not a loophole being exploited: it is how fund domicile works, and it is precisely why cross-border investors use Irish funds.

Why almost nobody knows

Four reasons this remains obscure despite affecting millions of investors:

Brokers do not raise it. It is a tax matter, not a suitability one, and disclosure obligations do not require it. Many brokerage staff are unaware of it themselves.

The information is US-centric. Most English-language investing content is written by and for Americans, for whom the multi-million exemption makes this a non-issue.

It is invisible until it is triggered. Nothing on a statement, a factsheet or a tax form flags it during the investor's lifetime.

The affected group is dispersed. Non-resident aliens investing in US markets are spread across dozens of jurisdictions with no common information channel.

The result is a widely-held, easily-avoided exposure that surfaces only when a family is least equipped to deal with it.

The remedy, and its cost

Hold Irish-domiciled UCITS funds instead of US-listed ones.

The cost of the remedy: a few basis points of higher TER, somewhat wider spreads, no listed options in most cases. Chapter 93 showed those costs are outweighed by the withholding advantage alone, before estate tax enters the picture. Once it does, the comparison is not close.

Other approaches exist and each carries complications worth understanding before pursuing:

Holding through a non-US company or trust can change situs, but introduces structuring costs, ongoing compliance, and potentially adverse treatment in the investor's own jurisdiction. This is professional-advice territory, not a DIY manoeuvre.
Staying below $60,000 in US-situs assets is technically effective and practically limiting for anyone with a meaningful portfolio.
Relying on a treaty, where one exists, requires understanding its specific terms: several provide relief through a pro-rated exemption rather than an exclusion.
Life insurance to cover the liability addresses the cash-flow problem without removing the exposure or the filing burden.

For the overwhelming majority of readers, the first option, simply buying the Irish version, solves the problem completely at negative net cost.

Four checks, three outcomes, one professional-advice flag. Most affected investors have never heard of the exposure; the checks take five minutes.

The scale of the problem

Consider how ordinary the exposed position is. An investor in Dubai or Kuala Lumpur reads that low-cost US index funds are the sensible core of a portfolio, which is true, opens an international brokerage account, and buys the famous US-listed fund at 0.03%. They have followed good advice from good sources and constructed a substantial, undisclosed US estate-tax liability.

Multiply that by the millions of non-US investors who have entered global markets over the past two decades, largely guided by American-authored content, and the aggregate exposure is enormous. The proportion who have addressed it is small.

This is, in this book's assessment, the single largest gap between what investors know and what they should know in the entire ETF landscape: larger than tracking difference, larger than withholding, larger than any product-selection question. It is also the easiest to fix.

A worked example

Rahim, 58, resident in Kuala Lumpur, holds $650,000 across three US-listed ETFs in an international brokerage account. Malaysia has no US estate-tax treaty.

If he dies holding this position:

US-situs assets: $650,000. Exemption: $60,000. Exposed: $590,000.
Graduated estate tax applies to the excess, producing a liability plausibly in the low-to-mid six figures depending on the computation.
His executors must file Form 706-NA and obtain a transfer certificate before the broker releases the assets: a process taking months, conducted in a foreign tax system, requiring US professional assistance.
His family, who did not know the exposure existed, discovers it while grieving.

If he switches to Irish UCITS equivalents:

One-time cost: capital gains in his jurisdiction (Malaysia does not tax capital gains on foreign securities, so effectively nil), plus spreads on the round trip, perhaps $600.
Ongoing cost: a few basis points more in TER, more than offset by the withholding saving of ≈0.17% a year (Chapter 93).
Estate exposure: zero. No filing, no delay, no liability.

He spends an afternoon and $600 to remove a six-figure risk while improving his expected returns. Very few decisions in investing have that shape.