Nothing on a British fund factsheet mentions the PFIC test. The status comes from American law applied to a foreign company, so no UK provider has any reason to flag it. That is why so many Americans in Britain discover the problem years after buying.
The good news is that the question is answerable in advance. This guide walks through what the tests actually look at, how to check a specific holding, and the two things people most often mistake for an answer.
What is the PFIC test?
It is a two-part test applied to a foreign corporation. One part looks at how much of its income is passive. The other looks at how much of its assets produce passive income. Meeting either one makes the company a PFIC.
Passive income here means the sort of return an investment produces rather than a trading business: dividends, interest, rents and gains. A fund exists to hold exactly those things, which is why funds are caught so reliably.
The instructions for Form 8621 set out the definition and the measuring rules, including how to value assets and how look-through applies to subsidiaries.
Why do British funds fail the PFIC test so often?
Because a collective fund is a foreign corporation whose whole purpose is holding investments. Its income is passive and its assets produce passive income, so it fails both limbs rather than scraping past one.
The wrapper makes no difference. A fund held inside an ISA, a general investment account or a workplace scheme is the same corporation either way. Our guide to ISAs and the PFIC problem covers the wrapper side of that.
Nor does the label. An investment trust, an OEIC, a unit trust and a UCITS ETF are different British structures, and the American analysis looks straight past those names to what the entity does.
| Holding | Usually caught? | Why |
|---|---|---|
| UK index fund or OEIC | Yes | A foreign corporation holding passive investments |
| UCITS ETF listed in London or Dublin | Yes | Same analysis, different structure |
| Investment trust | Usually | A company, but one holding passive assets |
| Shares in a trading company | Usually not | Its income comes from trading, not investments |
| US-domiciled fund | No | Not a foreign corporation |
Does UK reporting fund status settle it?
No, and this is the most common mix-up we see. Reporting fund status answers a British question about how gains are taxed here. It has no bearing on the American tests, which ask an entirely different question about the entity.
A fund can appear on HMRC's list of reporting funds and still be a PFIC. In practice most reporting funds are. The two systems are simply looking at different things.
So check both if you hold offshore funds. Reporting status affects your Self Assessment treatment, while the PFIC tests affect your American return and your paperwork.
Are individual shares safe?
Usually, though never say never. Shares in an ordinary trading company are not caught, because the company earns its money by trading rather than by holding investments. Most direct shareholdings therefore sit outside the regime.
The exception matters. A foreign company that is itself mostly passive can be a PFIC, even though you hold it as an ordinary share. Cash-rich holding companies and some investment vehicles fall on the wrong side.
In our practice we see this assumption stated too confidently in both directions. Check the company rather than the label, particularly where its balance sheet is dominated by investments.
How do you check a specific holding?
Start with domicile, then look at what the entity does. A fund domiciled in Ireland, Luxembourg or the UK is foreign for American purposes, which puts it inside the analysis before anything else is considered.
Then ask what the vehicle holds. A factsheet showing a portfolio of shares, bonds or property income tells you the income is passive. That answers the practical question for most retail funds.
Our PFIC checker walks through the same questions in order. It gives an indication rather than a ruling, though it settles the ordinary cases quickly.
What does look-through mean for fund structures?
It means the rules can look past one company to what sits underneath it. Where a fund owns enough of another company, the tests treat part of that company as if you held it directly. So a feeder structure does not hide the assets below it.
That matters for funds of funds and for the master-feeder arrangements common in Europe. The outer vehicle can look thin on its own, while the layer beneath holds exactly the passive assets the tests look for.
The instructions describe how the measuring works, including how to value assets for the purpose. Retail investors rarely need that detail, because the top-level answer is usually clear enough already.
Do ETFs and investment trusts differ?
Not in the way people hope. A London-listed ETF and an open-ended fund are different British structures, yet both are foreign corporations holding passive assets. The American analysis reaches the same conclusion for each of them.
Investment trusts feel different, because they are companies whose shares you buy on an exchange. That form does not save them either. What matters is what the company holds, not how you access it.
So the practical test stays the same in every case. Ask where it is domiciled and what it owns, then treat that answer as your starting point.
Checking a holding, step by step
Do this before you buy, not after. The treatment attaches to what you hold, and by the time you sell it is already fixed.
Keep the answers with your investment records. Next year you will want to know what you concluded and why.
- Find where the fund is domiciled, which the factsheet or KID states plainly.
- Confirm whether it is a corporation for American purposes rather than a partnership or trust.
- Look at what it holds and where its income comes from.
- Check whether any look-through applies through subsidiaries or feeder structures.
- Record your conclusion, the date, and the document you relied on.
- Repeat the check whenever you add a new holding or a fund restructures.
What happens once a holding is caught?
Reporting follows, and the default tax treatment is unkind. Without an election, gains and certain distributions fall under the excess distribution rules, which spread income back over your holding period and add an interest charge. The holding may also feed the values you report on Form 8938.
Two elections can improve that: treating the fund as a qualified electing fund, or marking it to market each year. Both have conditions, and the first needs information the fund may not provide.
Our guide to capital gains tax on shares covers the British side of a disposal. The elections themselves sit on the form, and their timing matters more than most people expect, since some options close once a year has passed.
Timing matters more than people expect. An election made in the first year you hold a fund behaves differently from one made later, so the calendar shapes your options as much as the fund does.
Does the PFIC test apply to pensions?
Pensions sit in a different place, and that is one reason they do so much work in cross-border portfolios. Funds held inside a recognized pension generally avoid the treatment that catches the same fund in an ordinary account.
The treaty supports that in defined ways, and the detail depends on the scheme. So a fund that would be a problem in a general investment account is often unremarkable inside a workplace pension.
That contrast is worth knowing before you invest. Where you hold something can matter more to the American result than what you hold.
How often should you re-run the check?
Once a year is usually enough for a settled portfolio, and immediately whenever you buy something new. A fund that passed the PFIC test when you bought it can change, because the tests look at what it holds each year rather than at what it was called.
Corporate actions deserve their own look. Mergers, reconstructions and share-class conversions can change the company underneath your holding, and the answer moves with it.
Keep a dated note of each conclusion beside your records. Reconstructing why you decided something four years ago is far harder than writing one line at the time.
That note also helps whoever prepares your return. It saves them repeating work you have already done, which shows up directly in the fee.
Common mistakes with the PFIC tests
The first is trusting the wrapper. An ISA changes the British tax, not the nature of the company inside it, so the American question survives untouched.
The second is reading reporting fund status as an all-clear. It answers a British question, and plenty of reporting funds are caught by the American tests.
The third is assuming a US-sounding brand means a US fund. A well-known American manager can run a Dublin-domiciled fund for European investors, and domicile is what counts.
An illustrative example
Take an illustrative example: an American in Bristol who buys a low-cost global index fund through a British platform. The factsheet mentions nothing American, and the fund appears on HMRC's reporting list, which reassures him.
The reporting status tells him how Britain will tax his gains. It says nothing about the American analysis. The fund is a foreign corporation holding passive assets, so the American tests catch it, and his return needs the extra form.
His colleague holds shares in a British engineering company instead. That company trades, so it sits outside the regime, and her American return treats the shares like any other stock.
What should you ask a platform before buying?
Three questions settle most cases, and none of them require a tax qualification to ask. Where is the fund domiciled, what legal form does it take, and does the manager produce annual information for American shareholders? Those three answers run the PFIC test for you in the ordinary case.
That third question decides your elections. Without the information, the better election is simply unavailable, and you are left with the default treatment for as long as you hold the fund.
Platforms rarely volunteer any of this. Asking in writing before you buy costs nothing, and it leaves you with a record of the answer you relied on.
The same questions work for a fund you already hold. If the answers are unwelcome, that is still better known now than at the point of sale.
How US UK Tax Hub helps
We review portfolios holding by holding through our US federal returns service, and we tell you which positions are caught before the filing season starts. Where elections are worth making, we model them rather than defaulting.
If you are about to invest, a short check first is far cheaper than a fix later. Send us the holdings and we will map the position at a fixed fee agreed first. For the wider reporting picture, see the IRS page on Form 8621 and our guide to Form 8938 and the FBAR. This article is general information, not personal tax advice; take advice on your own facts from a qualified US-UK adviser.
