Accountants & tax preparation for expats in the UK

Not automatically. Most employees taxed via PAYE do not need to file a return. However, if you have foreign income, self-employment income, rental income, investment gains, or income over £100,000, you must register for and file a Self Assessment return with HMRC. The deadline for online filing is 31 January following the end of the tax year. Late filing carries an immediate £100 penalty, rising significantly over time.

Yes. The US taxes on the basis of citizenship, not residence — so all US citizens and green card holders must file a US federal tax return each year regardless of where they live. Most US expats in the UK also need to file an FBAR (FinCEN 114) if their UK bank accounts exceed $10,000 at any point during the year, and may have FATCA reporting obligations. A specialist US expat tax service is strongly recommended to avoid penalties.

FBAR stands for Foreign Bank Account Report (formally FinCEN 114). It must be filed by any US person — citizen, green card holder, or resident alien — whose foreign financial accounts collectively exceeded $10,000 at any point during the calendar year. This includes UK current accounts, savings accounts, ISAs and investment accounts. FBAR is filed separately from your tax return, directly with the Financial Crimes Enforcement Network (FinCEN), and the deadline is 15 April with an automatic extension to 15 October.

Making Tax Digital is HMRC's programme to require businesses and self-employed individuals to keep digital records and submit tax information using compatible software. MTD for VAT already applies to all VAT-registered businesses. MTD for Income Tax Self Assessment (MTD ITSA) rolled out from April 2026, starting with self-employed individuals and landlords earning over £50,000. If you fall into this category, you will need MTD-compatible accounting software such as Sage, QuickBooks or Xero.

An IRS Enrolled Agent (EA) is a federally licensed tax practitioner who has passed a rigorous IRS examination and is authorised to represent taxpayers before the IRS. A Certified Public Accountant (CPA) holds a state-issued licence covering a broader range of accounting services, including audit and financial reporting. Both can prepare US federal tax returns and represent clients before the IRS. For US expats, either credential is appropriate — the key is finding a practitioner with specific experience in cross-border US-UK taxation, FBAR, and FATCA compliance, rather than a generalist.

If your tax position is straightforward — a single UK employer, no foreign income, no self-employment — self-filing via HMRC's online portal is manageable. Tax software such as TurboTax is a good middle ground for US expats who want step-by-step guidance without full accountant fees. If you have foreign income, overseas assets, self-employment income in multiple countries, or any cross-border complexity, a specialist expat accountant or IRS Enrolled Agent is worth the cost — errors and missed filings carry penalties that far exceed professional fees.

The UK-US double taxation treaty provides mechanisms to reduce or eliminate double taxation, primarily through foreign tax credits — you can generally offset UK tax paid against your US liability on the same income. However, the treaty does not eliminate the filing requirement: US citizens living in the UK must still file a US return every year. The treaty also has specific rules for different income types (dividends, pensions, rental income) that require careful application. Given the complexity, claiming treaty benefits correctly is one of the main reasons US expats benefit from working with a specialist rather than a generalist accountant.