Dual US-UK citizens: two systems, nothing taxed twice

Elections made on one return echo on the other for years: how a pension is characterised, whether credits or exclusions are claimed, how an investment account is reported. Change preparers, or split the returns between two firms, and the positions quietly diverge until a sale or a move exposes the gap.

One team keeps one file. The judgement calls made in year one are remembered in year three, and each year's returns are filed as a matched pair.

The natural investments of each country are the tax traps of the other: UK funds and ISAs raise PFIC issues for the US; some US funds are non-reporting for UK purposes and turn gains into income. Dual citizens need holdings selected to be efficient on both sides at once — the set exists, but it is narrower than either country's default menu.

Where a portfolio has already drifted into the traps, we quantify the exposure and restructure it in the least expensive order, rather than pretending the history away.

Selling a home, exercising options, inheriting, retiring — each event is taxed by both systems, on different timetables, sometimes in different tax years entirely. The currency of computation differs too: sterling for HMRC, dollars for the IRS, and exchange-rate movement alone can manufacture a US gain from a UK non-event.

The pattern that works is simple: tell us before the event, not after the tax year closes. Most double-tax outcomes are avoidable with sequencing; few are repairable after the fact.