Moving from the USA to the UK: The Tax Complexity No One Warns You About

For most people, leaving a country means leaving its tax system behind. For Americans, it does not. The United States is one of only two countries in the world (the other is Eritrea) that taxes its citizens based on citizenship rather than residency. This single fact makes the financial planning for Americans moving to the UK significantly more complex than for almost any other nationality.

The fundamental problem: you are taxable in both countries

As a US citizen living in the UK, you will generally be: - A UK tax resident, subject to UK income tax, capital gains tax, and potentially inheritance tax - A US person, required to file US tax returns and potentially pay US taxes on worldwide income

This creates an immediate double taxation risk. The good news is that the US-UK double taxation treaty helps mitigate this — but it does not eliminate it, and navigating it correctly requires specialist expertise.

FBAR and FATCA reporting

Beyond paying taxes, Americans abroad face extensive reporting requirements:

- FBAR (Foreign Bank Account Report): If your foreign financial accounts exceed $10,000 at any point during the year, you must file an FBAR. Penalties for non-compliance are severe. - FATCA (Foreign Account Tax Compliance Act): Requires reporting of foreign financial assets above certain thresholds. Also requires foreign financial institutions to report US account holders to the IRS — which is why some UK banks are increasingly reluctant to open accounts for Americans.

ISAs, SIPPs, and the US tax problem

UK tax-efficient wrappers like ISAs and SIPPs are not recognised as tax-advantaged by the US. The tax-free growth inside an ISA is potentially taxable in the US. Contributions to a SIPP may not be deductible for US tax purposes in the same way they are in the UK.

What you need

If you are an American moving to the UK, you need an adviser who holds specific expertise in US-UK cross-border taxation. This means understanding both the US Internal Revenue Code and UK tax law — a combination that relatively few advisers possess. Link Independent can connect you with specialists who do exactly this work.

The cost of getting it wrong

IRS penalties for non-filing and non-compliance can be substantial — sometimes exceeding the value of the accounts involved. This is not an area where you can afford to improvise.