PFICs and Form 8621: Why the US Penalises Non-US Funds and ETFs

What a PFIC is

A Passive Foreign Investment Company is any non-US corporation that meets either of two tests: at least 75 percent of its gross income is passive, or at least 50 percent of its assets produce passive income. Congress aimed the rules at offshore deferral schemes, but the tests are mechanical, and almost every pooled investment fund on earth meets them — a fund's whole business is holding passive assets.

So a FTSE tracker OEIC, a UCITS ETF, a unit trust, most investment trusts and many insurance-wrapped investments are PFICs to the IRS. The same portfolio built from US-listed funds would face none of this. The rules do not distinguish sensible investing from tax avoidance; they distinguish US funds from everyone else's.

Why the default treatment is so harsh

Under the default "excess distribution" regime, the tax system pretends your gain was earned evenly across your entire holding period, taxes each year's slice at the highest ordinary income rate for that year — capital gains rates never apply — and then charges interest on the tax attributed to earlier years, as if it had been due all along.

Hold a fund for a decade and sell at a gain, and much of the profit can disappear into tax and interest charges. Large "excess" distributions in a single year get the same treatment. Losses, meanwhile, get no symmetrical relief. It is one of very few places in the code where the arithmetic is deliberately punitive rather than merely strict.

Two elections can defuse the default. A QEF election taxes you annually on your share of the fund's income — but requires information statements most non-US funds do not produce. A mark-to-market election taxes annual gains in value as ordinary income — workable for regularly traded funds, but only if made early. Both work best from year one of ownership; retrofitting them later ranges from costly to impossible.

Form 8621: the paperwork

Each PFIC generally requires its own Form 8621 in any year you receive distributions, dispose of shares, or make or maintain an election — and an annual filing requirement applies above a de minimis level of total PFIC value even without any of those events. A portfolio of a dozen small fund holdings can mean a dozen forms, every year, each requiring calculations most tax software cannot do.

The forms sit alongside, not instead of, Form 8938 and FBAR reporting of the accounts that hold the funds. Unfiled Forms 8621 can also hold the statute of limitations open on your return.

ISAs: where UK logic meets US rules

The classic UK collision is the stocks and shares ISA. The UK sees a tax-free wrapper; the US sees a taxable account that usually holds PFICs — combining full US taxation with the worst version of it. Cash ISAs are harmless by comparison (just reportable interest), but investment ISAs deserve specific attention before, ideally, they are ever opened. Our guide to ISAs and investing as a US person in the UK covers what works instead.

What PFIC exposure actually costs

The damage arrives on three fronts at once, which is why the rules deserve their reputation. There is the tax itself — top ordinary rates plus interest charges on gains that would have been lightly taxed in a US fund. There is the compliance cost: PFIC calculations require purchase histories, distribution records and year-by-year workings that mainstream software does not attempt, so professional preparation of each form has a real price even when the holding is small. And there is the coordination problem — the UK may have taxed the same fund gains under its own rules, and lining up foreign tax credits against income the US has re-characterised and re-timed is rarely tidy. A small legacy holding can cost more to report correctly than it ever earned.

Living with the rules

The strategy that works is unglamorous: US persons generally hold funds through US-domiciled vehicles or direct shareholdings, keep non-US wrappers for cash, and treat any existing PFIC as a position to be measured and exited deliberately rather than discovered at sale. If you already own PFICs, the sequencing of sales, elections and foreign tax credits determines the real cost — which is precisely the calculation to run before acting, not after.