Find a Financial Advisor for British Expats in the U.S.: Q&A Insights from the Experts

The most common challenge we encounter is what we call the “two-system problem.” The US and UK tax systems operate entirely independently of each other, and decisions that make perfect sense on one side of the Atlantic can create serious problems on the other.

The clearest example is the UK ISA. For most British people, the ISA is simply a tax-free savings account, straightforward and familiar. But the US does not recognise the ISA as tax-advantaged. The IRS taxes the income and gains annually, and if the ISA holds funds rather than individual shares, those funds are likely classified as Passive Foreign Investment Companies, one of the most punitive tax categories in the US code. We regularly meet clients who have been filing US tax returns for years without realising any of this.

The way we work through this is to start with a complete picture of the client’s assets on both sides, US and UK, before making any recommendations. With the guidance of a tax advisor, we then map the tax treatment of each asset in both jurisdictions, identify where the exposures and inefficiencies are, and build a plan that addresses them in the right order. Sometimes the right move is to restructure. Sometimes it’s to close the ISA entirely. But it’s always a decision made with full information, not a guess.

The honest answer is: if you’re asking the question, you probably need one. But the more important question is whether you need a specialist.

In our experience, even good US advisors typically have little experience with cross-border clients. And a British expat is not a typical client. You may have a UK pension that doesn’t behave like a US retirement account. You have assets in two countries that are taxed differently in each. You have a retirement picture that spans two currencies and two sets of rules. A generalist advisor may handle the American side of your life perfectly well, but they’ll have no idea what to do with your SIPP, your ISA, or the inheritance tax implications of your UK property. And they won’t know what they don’t know, which is the most dangerous part.

Our rule of thumb is simple: if your financial life touches both countries in any meaningful way, and for most British expats in the US it does, you need someone who understands both. The cost of getting this wrong is almost always higher than the cost of good advice.

Cross-border financial planning is what we do. That means our team is familiar with the UK and US tax systems, the treatment of UK pensions and ISAs under US law, the UK/US Double Taxation Agreement, and the estate planning implications of having assets in both countries. When a client comes to us with a SIPP, we know what it is and we deal with them on a regular basis.

We also take a genuinely coordinated approach, working alongside specialist cross-border tax advisers, immigration attorneys, and estate planning professionals so that the advice our clients receive across all disciplines tells the same story. In our experience, British expats often have a US advisor and a UK accountant who have never spoken to each other. We improve that.

We always start with the same foundational question: how long do you plan to stay in the US? The answer shapes almost everything else. Someone who expects to return to the UK in five years needs a very different plan to someone who is staying in the US permanently. The tax implications of leaving the US as a long-term resident are significant and often overlooked.

From there, we ask about UK assets specifically: pensions, ISAs, property. Most advisors never ask about these. We do, because they’re often where the most significant planning opportunities and risks sit.

We also ask about citizenship and residency status. Are they a green card holder or a citizen? Have they considered the implications of each? And we ask what their retirement looks like: where they plan to be, what income sources they expect, and whether they’ve ever received a projection that accounts for both their UK State Pension and US Social Security together.

The common thread in all of these questions is that we’re trying to understand the full picture, not just the American slice of it.

Planning a return to the UK is one of the most complex financial events a British expat can face, and it’s one where early action makes an enormous difference.

The first thing to understand is the US exit tax. Long-term US residents, generally those who have held a green card for eight or more years, may be subject to an exit tax when they relinquish their status. This is calculated as if all worldwide assets were sold on the day of departure, and for someone with significant US retirement accounts, property, or investment portfolios, the liability can be substantial. Understanding this well in advance and structuring accordingly can significantly reduce the impact.

We also recommend reviewing UK pension drawdown strategy before leaving. The tax treatment of SIPP income changes depending on where you are resident, and timing distributions correctly can make a meaningful difference. Similarly, if appropriate, Roth conversions should ideally be completed while still in the US.

Finally, re-establishing UK tax residency brings worldwide income back into the scope of HMRC. US retirement account distributions, Social Security, and investment income all need to be considered through a UK tax lens from the moment you return. The earlier that planning begins, the more options you have.

The thing that continues to surprise us, even after working in this space for years, is how many British expats have been filing US tax returns for years without ever reporting their UK pensions, ISAs, or foreign bank accounts. Often it’s not because they were trying to hide anything. They simply didn’t know these needed to be reported, or they assumed their accountant had it covered.

The foreign account reporting requirements in the US are strict and the penalties for non-compliance are severe. FBAR filings, Form 8938, and in some cases Form 3520 for pension reporting are obligations that apply from day one of US tax residency, and missing them creates a problem that compounds with every passing year.

We also work with clients who are shocked to discover that their ISA is not tax-free in the US. For many British people, the ISA is simply part of the financial furniture. It’s always been there, it’s always been tax-efficient, and the idea that a different country might view it entirely differently simply hadn’t occurred to them. That moment of realisation, and the relief that tends to follow once we explain that it’s entirely fixable, is one of the most common and most memorable parts of the conversations we have with new clients.