Expat Money Mistakes: The Financial Errors New Expats Make

Moving abroad is one of the most financially consequential decisions a person can make. Done well, international relocation can dramatically accelerate wealth accumulation — lower taxes, higher salaries, lower costs, or all three. Done poorly, the same move can leave you worse off than if you had stayed in the UK, thanks to avoidable tax bills, banking errors, inappropriate investments, and the kind of complacency that comes from thinking "I'll sort it later."

This guide covers the most common and costly financial mistakes expats make — drawn from the experience of advising internationally mobile clients for over three decades. Recognise any of these in your own planning.

Mistake 1: Failing to Properly Sever UK Tax Residency

The UK Statutory Residence Test (SRT) is the legal framework that determines whether you are UK tax resident in any given year. Many people assume that simply moving abroad makes them non-resident. It does not.

You can become non-UK resident in the year of departure if you meet specific conditions — but you can also remain UK tax resident despite living abroad, particularly if you:

• Spend too many days in the UK (the automatic residence tests include a 183-day rule, but other tests can make you resident with far fewer UK days if you have UK ties such as a family home, a UK spouse, or UK employment)
• Hold property available for your use in the UK (your former home, or a property you did not rent out immediately)
• Fail to document your departure and ties correctly

The cost: If you remain UK tax resident, you are taxed on worldwide income including the income from your new country. This defeats much of the financial rationale for the move.

The fix: Take advice from a cross-border tax specialist before you leave — not after. Structure the timing of your departure, the use of UK property, and your UK visits around meeting the SRT non-residence conditions.

Mistake 2: Ignoring UK Filing Obligations After Departure

Becoming non-UK resident does not mean you can ignore HMRC. Non-resident individuals with UK income sources (rental income, UK employment, UK pension drawdown, some UK investments) must file UK self-assessment returns and pay tax on UK-source income.

Common oversights:

• Failing to file a UK self-assessment return in the year of departure (split-year treatment claims require a return)
• Not filing Statutory Residence Test assessments for borderline years
• Forgetting to report UK rental income while living abroad (HMRC increasingly identifies this via bank matching and Land Registry data)

The cost: Penalties for late filing and interest on unpaid tax — and in serious cases, HMRC investigations.

Mistake 3: Leaving UK ISAs and Pensions Misunderstood

ISAs. UK ISAs retain their tax-free status for UK tax purposes once you have moved abroad — you can keep your ISA and existing investments within it continue to grow tax-free. What you cannot do is make new ISA contributions once you are non-UK resident. The commonly repeated myth that you must close your ISA on departure is wrong — but the opposite myth that ISAs are automatically beneficial abroad is also wrong. If your new country of residence taxes ISA income and gains (as the US does, for example), the wrapper is irrelevant for local tax purposes.

Workplace pensions. If you leave UK employment to go abroad, your defined contribution workplace pension simply stops accumulating but remains invested. Employer contributions cease. As a non-UK resident with no UK relevant earnings, you can still obtain tax relief on personal contributions of up to £3,600 per year (gross) for the tax year in which you leave the UK and for the following five tax years, but check current HMRC rules before doing so.

Defined Benefit (DB) pensions. If you have a UK defined benefit pension, understand when it comes into payment, how it is taxed, and what the implications are of being non-resident when you draw it. The UK-destination country double tax treaty governs whether it is taxable in the UK, the destination, or both.

State Pension. Many expats forget their UK State Pension. You can top up voluntary National Insurance contributions as a non-resident to build towards the full new State Pension (worth approximately £241.30 per week, or about £12,548 per year, in 2026/27, payable from State Pension age — currently 66, rising to 67 between April 2026 and March 2028). The deadline for topping up earlier years periodically changes — check the current HMRC position. Many expats can pay the cheaper Class 2 rate; those who can only pay Class 3 face roughly £957 per year (2026/27) for each missing year. The ROI on these contributions is excellent for most people.

Mistake 4: Using the Wrong Investments for the Wrong Jurisdiction

UK-listed collective investments (unit trusts, OEICs, UK-listed ETFs) are typically categorised as Passive Foreign Investment Companies (PFICs) by US tax law. If you become US tax resident holding these, you face a punitive US tax regime on your UK funds that is disproportionately complex and expensive.

Similarly, many non-UK jurisdictions do not recognise UK ISA tax exemptions. Investing through a structure optimised for UK tax can be actively harmful in a different jurisdiction.

The fix: Review your investment portfolio before departure and restructure where necessary. Liquidating UK funds before becoming tax resident in the USA is one of the most important financial steps for UK-to-US movers. This is specialist territory — take qualified advice.

Mistake 5: Neglecting Exchange Rate Risk

Expats routinely underestimate exchange rate risk. If your income is in a foreign currency (AED, SGD, AUD, USD) and your obligations are in GBP (UK mortgage, children's UK school fees, UK pension contributions, sending money to support family), a 15–20% movement in the exchange rate can materially change your effective cost of living.

Common errors:

• Not hedging significant known future GBP obligations (e.g., remitting a lump sum to purchase a UK property in two years' time)
• Remitting money to the UK at random times using whatever rate the bank offers that day
• Holding too much cash in a foreign currency without a plan for when and how to convert it

Better approaches:

• Use forward contracts through an FX specialist (such as Currencies Direct or Moneycorp) to fix an exchange rate for future known currency needs
• Set up regular transfers on a recurring schedule rather than trying to time the market
• Consider whether holding assets in multiple currencies (a diversified currency position) suits your circumstances

Mistake 6: Over-Relying on Employer-Provided Financial Advice

Many expats are offered financial advice through their employer's relocation package or employee assistance programme. The quality of advice provided through these channels varies widely. Some employer-recommended advisers are excellent; others are tied agents of specific product providers and receive commissions that may not align with your interests.

When in doubt, seek independent advice from a fee-based adviser who is registered with the FCA (if providing UK financial advice) or with the relevant regulator in your destination country.

Mistake 7: Not Updating Wills and Estate Planning

A Will made in the UK may not be valid or optimally structured for an internationally mobile individual. Different countries have different succession laws (including forced heirship rules in France, Spain, and many EU countries under the EU Succession Regulation), different inheritance tax regimes, and different rules about the recognition of foreign Wills.

EU Succession Regulation (Brussels IV) allows EU residents to elect for their home country's law to apply to their estate — an important option for British expats resident in EU member states who want English law to govern their succession.

The fix: Review your Will with a solicitor who understands international succession. Some expats need separate Wills in each country where they hold significant assets. Power of attorney arrangements also need to be internationally considered.

Mistake 8: Assuming "I'll Sort it When I Get There"

The most expensive financial planning is retroactive financial planning. Errors in tax departure, investment structure, pension contributions, and banking are far more costly to fix than they are to prevent. Many mistakes have a statute of limitations — by the time you realise the error, you cannot unwind it.

The correct time to take advice is before you leave, not after your first foreign tax return arrives.

Mistake 9: Underestimating the Cost of Living Abroad

Expats regularly underestimate costs. The "affordable" destination turns out to have:

• High school fees not covered by the employer package
• International health insurance costs of £500+ per month for a family
• A cost of living 20% higher than anticipated once you factor in Western shopping habits in a non-Western city
• Flights back to the UK for family visits four times per year at £1,200+ per person
• Home maintenance costs for a UK rental property (10% of rental income on average)

Build a realistic financial model before you go — and build in a 20% buffer.

Mistake 10: Not Planning for Return

A significant percentage of expats eventually return to the UK — whether planned from the outset or triggered by family events, health, career changes, or simply life. Returning to the UK as a previously non-resident individual can trigger UK tax charges on:

• Remittances to the UK of overseas income if you were previously using the remittance basis
• UK residential property disposals where the principal private residence exemption requires careful calculation for periods of non-residence
• Assets held offshore that must be revalued on return

The year of return to UK tax residency is one of the most financially complex tax years an individual can have. Plan the return with as much notice and specialist advice as possible.

How Global Investments Can Help

Avoiding the mistakes above requires integrated financial planning across tax, investments, pensions, estate planning, and currency management — precisely the multi-disciplinary advisory service Global Investments provides for internationally mobile clients. With over three decades of experience advising internationally mobile clients across major markets worldwide, our team has seen these errors often enough to know how to prevent them.

Speak to us before you move. The conversation costs you nothing; the mistakes it prevents can cost you far more.

This guide is for general information only. Tax rules, financial regulations, and investment conditions change frequently and vary by jurisdiction. Nothing in this guide constitutes financial, tax, or legal advice. Always seek professional advice tailored to your specific circumstances before making financial decisions. Investments can fall as well as rise in value.