Introduction
Living across borders – whether you are a UK citizen moving abroad, a foreign national coming to the UK, or someone who spends time in multiple countries – creates complex tax obligations. The UK taxes residents on their worldwide income and gains. Non‑residents are generally taxed only on UK‑source income (e.g., UK property rental, UK employment). But determining your residency status is not always simple, and failing to understand your filing obligations can lead to penalties and double taxation. This guide covers the essential UK tax rules for cross‑border residents, including the Statutory Residence Test, the remittance basis, double taxation treaties, and reporting obligations.
Based on rules as of June 2026. Always verify current rates with official sources.
Step 1: Determine Your UK Residency Status
Residency for UK tax purposes is determined by the Statutory Residence Test (SRT) . It is a complex set of rules, but the key questions are:
Automatic UK resident (you are definitely resident) if:
- You spend 183 days or more in the UK in the tax year.
- Your only home is in the UK (and you have no home overseas).
- You are a full‑time worker in the UK (with no significant work overseas).
Automatic non‑resident (you are definitely not resident) if:
- You spend fewer than 16 days in the UK (or fewer than 46 days if you were not resident in the previous 3 years).
- You work full‑time overseas and spend fewer than 91 days in the UK, with no more than 30 days working in the UK.
Sufficient ties test (for people between 16–182 days): If you do not meet the automatic tests, you count “ties” to the UK – family, accommodation, work, 90‑day presence in previous years, etc. The more ties, the fewer days you can spend in the UK without becoming resident.
Example: A UK citizen who moves to France but keeps a flat in London, has a spouse in the UK, and spends 120 days in the UK may be resident because of the ties.
Action: Use HMRC’s online residency checker (on GOV.UK) or consult a tax adviser if your situation is complex. Residency determines whether you pay UK tax on worldwide income.
Step 2: Understand Your Tax Liability Based on Residency
UK resident: You pay UK tax on your worldwide income and capital gains. However, double taxation treaties may give credit for tax paid overseas (see Step 4). You also have access to UK allowances (Personal Allowance, ISA, etc.) but not if you are non‑resident (some allowances are restricted).
Non‑resident: You pay UK tax only on UK‑source income, typically:
- UK employment income – if you work in the UK, even for a few days.
- UK property rental income – from a property you own in the UK.
- UK trading income – if you carry on a trade in the UK (e.g., via a UK branch).
- UK pension income – some pensions are taxed at source.
- UK savings and dividend income – generally not taxable for non‑residents, with exceptions (e.g., interest from UK bonds may be taxable).
Non‑resident capital gains: Since April 2015, non‑residents have been subject to Capital Gains Tax on disposals of UK residential property (and from April 2019, on disposals of UK property‑rich entities). Other assets (e.g., shares in UK companies) are generally not taxable for non‑residents.
Step 3: The Remittance Basis (For Non‑Domiciled Residents)
If you are a UK resident but your “domicile” is outside the UK (typically because you were born abroad and intend to return), you may claim the remittance basis of taxation. This means you pay UK tax only on UK income and gains, plus any foreign income or gains that you “bring to” (remit to) the UK.
Cost of claiming the remittance basis:
- If you have been UK resident for fewer than 7 of the last 9 tax years: no charge.
- If you have been UK resident for 7 of the last 9 years: you pay a charge (for illustration, £30,000 – check current).
- If 12 of the last 14 years: £60,000 charge.
- If 15 of the last 20 years: you become deemed domiciled – the remittance basis is no longer available (you are taxed on worldwide income regardless).
When is the remittance basis useful? If you have significant foreign income or gains that you do not need to bring to the UK, and you are willing to pay the charge to keep that income offshore. For most people, the remittance basis is not worthwhile – it is simpler to pay UK tax on worldwide income and claim double taxation relief.
Action: If you are a non‑domiciled resident, seek professional advice. This area is complex and penalties for incorrect claims are severe.
Step 4: Double Taxation Treaties
The UK has double taxation treaties with most countries (including the US, Canada, Australia, most of Europe, and many others). These treaties determine which country has the right to tax different types of income and provide relief for tax paid in the other country.
Common tie‑breaker rules: For individuals resident in both countries (e.g., because they spend significant time in both), the treaty typically looks at:
- Permanent home (where you have a home available).
- Centre of vital interests (where your family, finances, and social ties are strongest).
- Habitual abode (where you spend more time).
- Nationality (if all else fails).
How relief works: If you pay tax in Country A on income that is also taxable in the UK, you can claim a foreign tax credit against your UK tax liability (or vice versa). This prevents double taxation.
Example: You live in France but work remotely for a UK company, spending 60 days in the UK. Under the UK‑France treaty, your employment income may be taxable only in France (if you spend fewer than 183 days in the UK and the employer is not UK‑based? – actually, the rules are detailed). The key point: you do not pay tax twice.
Action: Look up the specific treaty between the UK and your other country (available on GOV.UK). For most common situations, HMRC’s guidance is sufficient. For complex cases, consult a cross‑border tax adviser.
Step 5: Filing Obligations for Non‑Residents
Even if you are non‑resident, you may need to file a UK Self Assessment tax return if you have:
- UK employment income (and your employer does not operate PAYE correctly – but most do).
- UK property rental income (even if it is below the Personal Allowance – you must file).
- UK capital gains on residential property (non‑residents must report and pay CGT within 60 days of completion – a strict deadline).
- A claim to the remittance basis (you must file a return even if no tax is due).
How to file: You can file online via HMRC’s Self Assessment portal. You will need a Unique Taxpayer Reference (UTR). If you do not have one, register as a non‑resident taxpayer using form NR1 (or online, if available).
Deadlines: For the tax year ending April 5th, the online filing deadline is January 31st of the following year. For non‑residents with UK property income, the deadlines are the same. For non‑resident CGT on UK property, the deadline is 60 days from completion (not the usual January 31st).
Step 6: UK Nationals Moving Abroad – Leaving the UK
If you are a UK citizen moving abroad permanently (or for an extended period), you need to:
Notify HMRC: Use form P85 (online or paper) to tell HMRC that you are leaving the UK. This helps them adjust your tax code and determine your residency status.
Settle any tax due: If you owe tax on income or gains before leaving, pay it. If you are due a refund, HMRC will issue it.
Check your pension: You can keep your UK pensions. If you take a pension lump sum after leaving, it may be subject to UK tax at source (or to tax in your new country under the treaty). Some people transfer their UK pension to a Qualifying Recognised Overseas Pension Scheme (QROPS) – but this is complex and often not worthwhile.
ISAs: You can keep existing ISAs, but you cannot contribute to them once you are non‑resident (unless you are a Crown employee overseas). The tax‑free status is generally respected, but your new country may tax ISA growth.
State Pension: You can still claim your UK State Pension if you move abroad. It will be paid into a foreign bank account and uprated annually only if you live in certain countries (within the EEA, or countries with a social security agreement). If you move to Australia or Canada, for example, the State Pension is frozen at the rate when you left.
Capital gains on main residence: If you sell your UK home after moving abroad, you may be subject to non‑resident CGT (even if it was your main residence). However, private residence relief may still apply for the period you lived there, and you may have an additional 9 months of relief after moving out.
Step 7: Foreign Nationals Coming to the UK
If you move to the UK from abroad, you become a UK resident based on the SRT (see Step 1). Your tax liability depends on your domicile status (see Step 3).
What to do:
- Apply for a National Insurance number (if you will work).
- Register for Self Assessment if you have complex income (foreign income, rental, self‑employment).
- Consider whether to claim the remittance basis if you are non‑domiciled.
- Check whether your foreign pension is taxable in the UK – most foreign pensions are taxable, but double taxation relief applies.
Temporary non‑resident rules: If you leave the UK and then return within 5 years (or less, depending on circumstances), certain capital gains realised while you were non‑resident may be clawed back and taxed in the UK. This is a niche area – seek advice if you plan to return.
Step 8: Getting Professional Help
Cross‑border tax is one of the few areas where professional advice is often worth the cost. A single mistake (e.g., failing to file a non‑resident CGT return on time) can result in penalties of £100 or more, plus interest.
Where to find help:
- Chartered Institute of Taxation (CIOT) – Find a chartered tax adviser.
- Association of International Accountants (AIA) – Some specialise in cross‑border.
- HMRC’s Residence, Domicile and Remittance Basis unit – For complex cases, you can call them (but they cannot give tailored advice).
Cost: Expect £200–£500 per hour for a specialist cross‑border tax adviser. A one‑hour consultation to determine your residency status and filing obligations is often sufficient.
Key Takeaways
- Residency is determined by the Statutory Residence Test – days in the UK and ties matter.
- UK residents pay tax on worldwide income – non‑residents pay only on UK‑source income.
- Non‑domiciled residents may claim the remittance basis – but there is a charge after 7 years.
- Double taxation treaties prevent paying tax twice – claim foreign tax credits.
- Non‑residents with UK property income or gains must file returns – and CGT on property has a 60‑day deadline.
- Seek professional advice – cross‑border tax is complex and penalties are severe.
This article is for general information and educational purposes only. It does not constitute financial advice. Tax rules, allowances, and product terms may change. Always check with HMRC or an FCA-authorised adviser for your personal circumstances.