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US citizens in the UK · Tax basics

PFIC: why US citizens avoid UK funds

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Almost every UK fund is a PFIC, and the US taxes PFICs punitively. Top-rate tax, an interest charge for the years you held it, and heavy annual filing. This is the single biggest reason US citizens avoid UK funds and fund-holding ISAs.

A PFIC, a passive foreign investment company, is the US tax label for a pooled investment fund based outside the US. The definition is broad enough to catch nearly all UK and European collective funds: unit trusts, OEICs, investment trusts, and London-listed ETFs almost always qualify. If it is a non-US fund holding other people's pooled money, assume it is a PFIC.

Why the tax is so harsh

The US built the PFIC rules to stop Americans deferring tax inside offshore funds, and the default regime is deliberately unattractive. Gains and certain distributions are taxed at the highest ordinary rate rather than the lower capital-gains rate, and an interest charge is added as if the tax had been owed across every year you held the fund. The result can take a large bite out of a perfectly ordinary investment return.

The filing burden

Each PFIC generally needs its own Form 8621 every year. Hold a handful of UK funds and the annual filing alone becomes a real cost, before any tax. Some elections can soften the treatment, but they depend on the fund providing US tax information that most UK funds simply do not.

What US persons hold instead

The common answer is to avoid non-US funds altogether: hold individual shares, or US-domiciled funds and ETFs bought through a US-friendly account, neither of which is a PFIC. This is why a UK ISA or platform that only offers UK funds rarely helps an American, even when the account itself is open to you.

PFIC is the rule behind the stocks and shares ISA and brokerage pages.

Common questions

What is a PFIC?

A PFIC, or passive foreign investment company, is the US tax label for a pooled investment fund based outside the US. The definition is broad enough to catch nearly all UK and European collective funds: unit trusts, OEICs, investment trusts and London-listed ETFs almost always qualify. If it is a non-US fund holding other people's pooled money, assume it is a PFIC.

Why is PFIC tax so punitive?

The rules exist to stop Americans deferring tax inside offshore funds, so the default regime is deliberately unattractive. Gains and certain distributions are taxed at the highest ordinary rate rather than the lower capital-gains rate, and an interest charge is added as if the tax had been owed across every year you held the fund.

Can a US citizen hold a UK index fund or ETF?

You can, but the US taxes it as a PFIC, which usually outweighs any UK benefit. Each PFIC generally needs its own Form 8621 every year, so a handful of UK funds becomes a real annual cost before any tax is due. Some elections soften the treatment, but they depend on the fund providing US tax information that most UK funds do not.

What do US citizens in the UK hold instead of UK funds?

Individual shares, or US-domiciled funds and ETFs bought through a US-friendly account, neither of which is a PFIC. This is why a UK ISA or platform that offers only ready-made fund portfolios rarely helps an American, even when the account itself opens for you.

Confirm your own position with a cross-border specialist. Acceptance policies and tax rules change, and your facts may differ from the general case. Rates and terms here are the provider's published figures rather than an offer, and the provider decides each application on its own criteria. Use this as a map, not a ruling. Last checked .
Accounts

Stocks & shares ISAs

Most UK funds in a stocks and shares ISA are PFICs, which the US taxes punitively. Which providers accept US citizens, and why the wrapper rarely helps.

 Accounts

Brokerage accounts

Most UK investment platforms decline US persons. The ones that accept you, what they let you hold, and the PFIC trap on UK-domiciled funds.

 Accounts

SIPPs

A SIPP can work for a US citizen, but most providers restrict what you can hold. Which SIPPs accept you, and how the treaty protects the wrapper.

 Tax

ISA US tax

The IRS does not recognise the ISA wrapper. Cash ISA interest and stocks ISA gains are taxable on your US return, and fund holdings drag in PFIC rules.

 More

Where to save

Savings accounts, cash ISAs, Premium Bonds, stocks and shares ISAs and pensions side by side for a US citizen in the UK: who opens each, the UK tax, the US tax and what gets reported.