PFIC
A PFIC (Passive Foreign Investment Company) is a foreign corporation meeting either the 75% passive-income test (75%+ of gross income is passive) or the 50% passive-asset test (50%+ of assets produce or are held for production of passive income). US persons holding PFIC stock face punitive default tax treatment under §1291 unless they elect into QEF (Qualified Electing Fund) or mark-to-market regimes.
The PFIC rules exist to prevent US persons from using foreign investment vehicles to defer US tax on passive income — without them, a US taxpayer could shift portfolio holdings into a foreign mutual fund and indefinitely defer recognition of dividends and capital gains. The default treatment under §1291 imposes deferred-tax interest charges that effectively neutralize the deferral benefit, making the default regime almost always worse than holding the same assets in a US-domiciled vehicle.
Three regimes are available: (1) Default (§1291) — 'excess distributions' (above 125% of the 3-year average) are allocated pro-rata across the holding period, taxed at the highest ordinary rate plus interest; (2) QEF (§1295) — annual flow-through of the PFIC's income (ordinary and capital gain), taxed currently regardless of distribution; (3) Mark-to-market (§1296) — for marketable PFIC stock, annual mark-up taxed as ordinary income, mark-down deductible as ordinary loss to the extent of prior mark-ups. The QEF election is generally most favorable but requires the foreign fund to provide an Annual Information Statement (AIS) — most non-US-domiciled funds do not.
The practical impact for US persons holding non-US mutual funds or ETFs (including many UCITS funds, common in expat retirement accounts) is severe. A US taxpayer with a UK-resident pension holding UK-domiciled equity funds typically owes PFIC tax annually with no information from the fund — requiring estimated reporting and acceptance of the punitive default §1291 treatment. The compliance cost alone (Form 8621, often $500–$2,000 per fund per year in CPA fees) makes holding PFICs prohibitively expensive for most US-person expats.
Synthetic households with cross-border or expat scenarios need PFIC flag tracking on foreign holdings. The data should distinguish QEF-elected, mark-to-market-elected, and default-§1291 treatment; each has different tax computation and reporting requirements (Form 8621 in all cases). Realistic households should include the common expat trap of UK or EU UCITS funds held by a US person.
Common pitfalls
- Treating non-US mutual funds and ETFs as if they had standard mutual-fund US tax treatment — most are PFICs and the default regime imposes deferred-tax interest charges.
- Missing the Form 8621 filing requirement — required for each PFIC held, regardless of whether distributions occurred.
- Failing to obtain a QEF Annual Information Statement before the QEF election deadline (first day held) — once missed, you can't retroactively elect QEF.
- Treating PFIC dispositions as capital gains — under default §1291 they are taxed as ordinary income with interest charges, not as capital gains.
Examples
US citizen living in UK holds £100,000 of a UK-domiciled equity fund inside a UK ISA. The ISA is tax-free in the UK; under US law, the PFIC provisions still apply because the holder is a US person. Annual Form 8621 required. If the UK fund doesn't provide a QEF AIS, the holder is stuck with default §1291 treatment — severe punitive taxation on any 'excess distribution', plus interest charges accruing across the holding period. Net: the ISA's UK tax-shelter benefit is more than wiped out by the US PFIC cost.