If you're an American moving to the UK — or a British citizen coming home after decades in the States — the timing of your arrival has quietly become one of the most valuable facts in your tax life. Since April 2025, the UK offers qualifying new residents something genuinely unusual: a four-year window in which foreign income and gains can escape UK tax entirely, with no penalty for bringing the money into the country.
It's called the FIG regime, and for the right person it's worth a great deal. But it is a decision, made each year, with a real price attached — and that's the part most summaries skip.
Who gets the window
The test is simple to state: you qualify if you become UK resident after ten consecutive tax years of non-residence. A New Yorker arriving for the first time qualifies. So does a Briton returning after thirty years in California — the passport doesn't matter; the decade away does. The window runs for your first four tax years of residence, and the clock starts whether or not you claim.
What claiming actually does
For each year you claim, your qualifying foreign income and gains — US dividends, interest, capital gains, certain pension events — are simply outside UK tax. In exchange, you give up your UK personal allowance and your capital gains exempt amount for that year. For someone with substantial US investment income and modest UK income, that trade is excellent. For someone whose income is mostly UK salary with a little US interest on the side, it can lose. Married couples can land on opposite sides of the line — the claim is made per person, per year, and should be modelled that way.
Why Americans should care most of all
Here's the nuance: as a US citizen, you'll pay American tax throughout regardless — FIG shelters only the UK side. So its value concentrates on income the US taxes lightly — qualified dividends, long-term gains — where the UK's higher rates would normally top up the bill. And it creates once-only planning windows: certain restructurings of US accounts, done during the FIG years, carry a combined tax cost dramatically lower than the same move made in year five. Those opportunities expire with the window, and the window is already running from the day you arrive.
The honest summary
FIG is neither a loophole nor a formality. It's a per-year decision that rewards people who model it and quietly costs people who assume it. If you've arrived in the UK since April 2025 — or you're planning the move — the modelling belongs in year one, because year one is already one quarter of the window.
We prepare exactly this analysis, separately for each spouse, alongside the returns themselves.