Can You Be Tax Resident in Two Countries?

If you're working across borders, relocating abroad, or splitting your time between countries, you've probably wondered: can I actually be tax resident in two places at the same time? The short answer is yes: and it happens more often than you might think.

Dual tax residence occurs when you meet the residency criteria of two different countries simultaneously. This isn't a loophole or an error; it's simply the result of countries applying their own domestic rules independently. Understanding how this works: and what to do about it: is essential for anyone with international ties.

Why Dual Residence Happens

Countries don't coordinate their tax residency tests. Each jurisdiction applies its own criteria to determine who qualifies as a resident for tax purposes. In the UK, residency is governed by the Statutory Residence Test (SRT), a detailed framework that considers factors such as:
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• The number of days you spend in the UK during a tax year
• Whether you have ties to the UK (family, accommodation, work, or 90-day ties)
• Your work patterns and location
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Other countries take different approaches. Many jurisdictions use a simple 183-day rule: if you spend 183 days or more in the country during a calendar year, you're automatically tax resident. Others look at where you have a permanent home, where your economic interests lie, or where you're registered as a resident.
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Because these tests operate independently, you can easily satisfy the requirements of both the UK and another country in the same tax year. For example, you might spend 120 days in the UK (enough to trigger UK residence under certain SRT scenarios) while also spending 190 days in Spain (triggering Spanish residence under their 183-day rule).

The UK's Statutory Residence Test vs Other Countries

The UK's approach to residency is notably complex compared to most jurisdictions. The SRT doesn't rely on a single bright-line test. Instead, it uses:
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• Automatic overseas tests that make you non-resident regardless of other factors
• Automatic UK tests that make you resident regardless of other factors
• Sufficient ties tests that combine day counts with specific connections to the UK
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This multi-layered structure means you can be caught as a UK resident even if you spend fewer than 183 days in the country: particularly if you have accommodation available, family in the UK, or substantive work ties.

In contrast, most countries apply simpler tests. Portugal, for instance, considers you resident if you spend more than 183 days in the country or maintain a habitual residence there. The UAE has no personal income tax and no formal residency test for tax purposes (though visa residency is separate). France uses the 183-day rule alongside tests for your principal home and professional activity.

This asymmetry creates natural opportunities for dual residence. You might leave the UK partway through the tax year, satisfy the automatic overseas test for the UK, yet still trigger residency in your new country under their domestic law.

Double Taxation Agreements and Tie-Breaker Rules

When you're tax resident in two countries under their respective domestic laws, both jurisdictions may try to tax your worldwide income. This is where Double Taxation Agreements (DTAs) become critical.

DTAs are bilateral treaties designed to prevent the same income being taxed twice. Most agreements follow the OECD Model Tax Convention, which includes Article 4: the tie-breaker provision for dual residents.
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Article 4 establishes a hierarchy of tests to determine which country has primary taxing rights over you. These tie-breaker rules typically apply in the following order:

1. Permanent Home Available
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The first test looks at where you have a permanent home available to you at any time. If you have a home in only one country, that country wins. If you own or rent property in both countries, the test moves to the next level.

2. Centre of Vital Interests
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This examines where your personal and economic ties are strongest. The analysis considers:

• Where your family lives
• Where your main assets are located
• Where you conduct your professional activities
• Where you participate in social and political life

3. Habitual Abode
If your vital interests can't be determined: for instance, if they're equally split: the test looks at where you habitually reside. This is generally where you spend the most time or maintain your routine.

4. Nationality
If all else fails, nationality becomes the deciding factor. If you hold citizenship in both countries (or neither), the tax authorities must reach a mutual agreement.

Importantly, the tie-breaker determines your treaty residence, not your domestic tax residence. This is a crucial distinction.

Tax Resident vs Treaty Resident: What's the Difference?

Many people mistakenly believe that if a DTA determines you're treaty-resident in Country A, you're automatically no longer tax resident in Country B. This isn't how it works.

Tax residence is determined purely by domestic law. If you meet the criteria under the UK's Statutory Residence Test, you are a UK tax resident: full stop. If you also meet Spain's 183-day rule, you are also a Spanish tax resident. Both statuses exist simultaneously.

Treaty residence is a separate concept that applies only when a DTA is invoked. It determines which country has the primary right to tax certain types of income when both countries claim taxing rights. Think of it as a casting vote, not an override.
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For example, you might be:

• A UK tax resident under the SRT (because you have sufficient UK ties and spent 100 days in the UK)
• A Portuguese tax resident under Portuguese law (because you spent 200 days there)
• Treaty-resident in Portugal under the UK-Portugal DTA (because your centre of vital interests is in Portugal)
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In this scenario, you would still need to report your UK residence status to HMRC. However, the DTA would provide relief from double taxation, typically by:

• Exempting certain income from UK tax
• Reducing taxing rights on certain income from UK tax
• Requiring Portugal to credit UK tax on UK income
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This distinction matters because it affects your filing obligations, disclosure requirements, and how you claim relief. You can't simply ignore HMRC because a DTA makes you treaty-resident elsewhere.

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Practical Implications of Dual Residence

Being tax resident in two countries creates several practical challenges:

Filing obligations multiply. You may need to submit tax returns in both jurisdictions, report worldwide income in each, and track which income has already been taxed where.

Timing differences complicate matters. The UK tax year runs from 6 April to 5 April, while most countries use the calendar year. This mismatch means your dual residence period in one country's terms may not align with the other's.

Split Year Treatment may apply if you're arriving in or leaving the UK partway through the tax year. If you qualify, the UK tax year is divided into a resident portion and a non-resident portion, with different rules applying to each. This can reduce the overlap period during which you're resident in both countries: though it doesn't eliminate dual residence entirely if the other country considers you resident for their full tax year. You can learn more about how to apply for this treatment here.

Social security contributions may also be affected. Within the EU and certain other countries, social security treaties determine where you pay national insurance or equivalent contributions. These treaties operate separately from income tax DTAs and use their own residency tests.

What You Should Do

If you suspect you're tax resident in two countries simultaneously, your first step is to confirm your status under each country's domestic law. For the UK, this means applying the Statutory Residence Test carefully: many people make common mistakes when self-assessing their position.

Once you've established dual residence, identify whether a DTA exists between the two countries. Not all country pairs have treaties, and those that do may have different provisions. Review Article 4 to determine your treaty residence based on the tie-breaker rules.
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You should then:

• Determine your filing obligations in each country
• Identify which income types are taxable where under the treaty
• Calculate whether you're entitled to foreign tax credits or exemptions
• Consider whether Split Year Treatment or the FIG regime applies to reduce your exposure
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Given the complexity involved: and the severe penalties for getting it wrong: we recommend obtaining specialist UK tax advice for expats who can analyze your specific circumstances across both jurisdictions.
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Final Thoughts

Dual tax residence isn't unusual, nor is it necessarily problematic: providing that you understand your position and structure your affairs accordingly. The tie-breaker rules in Double Taxation Agreements exist precisely because lawmakers anticipated this scenario.

What matters is that you correctly identify when dual residence applies, understand how the DTA allocates taxing rights, and meet your obligations in both countries. Whether you're relocating, working remotely across borders, or gradually transitioning between countries, getting this right from the outset will save you considerable time, cost, and stress.