Tax Residency vs Domicile vs Residence Permit: What’s the Difference?

Understanding these concepts is essential for expats, remote workers, founders, and international families because each one affects your taxes, immigration rights, and legal obligations differently.

For example, you can hold a UK residence permit without becoming a UK tax resident. Or you may remain domiciled in the US while living abroad for years. These distinctions matter when navigating income taxes, inheritance rules, double taxation treaties, and visa planning.

In this guide, we break down what tax residency, domicile, and residence permits actually mean — and how they interact in real-life scenarios across the US, UK, Portugal, and UAE.

What Is Tax Residency?

Tax residency — sometimes called fiscal residency or tax resident status — determines which country has the right to tax your worldwide income. Every country sets its own rules for deciding whether you qualify.

In practice, tax residency is usually based on:
◾ The number of days you spend in a country
◾ Where your permanent home is located
◾ Your family and economic ties
◾ Where your "center of vital interests" exists

Many countries apply some version of the 183-day rule, but the actual tax residency rules are often more nuanced than a simple day count.

The UK Tax Residency System

The UK uses the Statutory Residence Test (SRT) to determine tax residency.

The test weighs:
◾ How many days you spend in the UK
◾ Whether you have a home there
◾ Work connections in the country
◾ Personal ties such as close family members

Importantly, you can become a UK tax resident even if you spend fewer than 183 days in the country — if your connections are strong enough. The SRT is one of the more complex frameworks globally, and getting it wrong is expensive.

The US Tax Residency System

The US applies two main routes to tax residency:
◾ The Substantial Presence Test, which uses a weighted formula counting days spent in the US over a three-year period
◾ Holding a US Permanent Resident Card (green card)

Unlike most countries, the US also taxes its citizens regardless of where they live. This means a US citizen living in Dubai or Lisbon may still need to file US tax returns — even after becoming a tax resident elsewhere.The same applies if you're relocating to Canada — US citizens moving to Canada face the same citizenship-based filing obligations. Provisions like the Foreign Earned Income Exclusion (FEIE) can reduce the actual tax owed, but the filing obligation remains.

What Is Tax Domicile?

Domicile — also referred to as tax domicile in some contexts — is a broader legal concept connected to your permanent home and long-term intentions. Unlike tax residency, domicile is rarely determined by counting days in a country.

A person generally acquires:
◾A domicile of origin at birth
◾A domicile of choice, established by permanently settling in another country with the genuine intention to remain there indefinitely

Changing domicile requires proving both a physical relocation and a clear intention to make the new country your permanent home. This is a high legal bar that many long-term expats never actually clear.

Domicile vs Tax Residency: The Key Difference

This is where most people get confused.

You can live in another country for years, become a tax resident there, and still remain domiciled in your original country. The two statuses are legally independent.

For example:
◾ A US citizen living in the UK for ten years may still be considered US-domiciled for estate tax purposes
◾ A UK citizen working temporarily in New York may remain UK-domiciled even while paying US income tax

Domicile also connects closely to concepts such as habitual abode and the center of vital interests — terms that appear frequently in tax treaties when resolving dual residency disputes.

Why Domicile Matters

Domicile most commonly affects:
◾ Inheritance taxes and estate planning
◾ Succession law (which country's rules govern your assets)
◾ Certain wealth tax rules
◾ In the UK, access to the historical non-dom regime

The UK Non-Dom Regime (A Key Example)

Under rules that applied for many years, a person could live and work in the UK, qualify as a UK tax resident, and still remain domiciled abroad. This historically allowed certain individuals to avoid UK taxation on foreign income unless it was brought into the country — a treatment known as the remittance basis.

This is one of the clearest real-world examples showing that tax residency and domicile are entirely separate legal statuses that can coexist.

What Is a Residence Permit?

A residence permit is an immigration document that gives someone the legal right to live in a country temporarily or permanently. It is issued by immigration authorities, not tax authorities, and serves an entirely different purpose from the other two concepts.

Common examples include:
◾ UK Skilled Worker visas
◾ US Permanent Resident Card (Green Card)
◾ Portugal's D7 Passive Income Visa or Digital Nomad Visa
◾ UAE residence permits and Golden Visas
◾ Temporary and permanent residency permits across the EU, as outlined by the EU Immigration Portal

Temporary vs Permanent Residence Permits

A temporary residence permit typically has an expiration date, may depend on employment or study, and can include conditions or restrictions. A permanent residence permit allows long-term residence with greater stability and often creates a pathway toward citizenship.

Does a Residence Permit Create Tax Residency?

Not automatically — and this is one of the most common and costly misconceptions among expats.

A person can hold a residency permit but spend too little time in the country to trigger tax residency. Conversely, someone may spend enough time in a country to become a tax resident without ever holding a formal long-term permit.

Tax authorities typically evaluate time spent in the country, economic ties, and personal connections — independently of what any immigration document says.

Comparing the Three Concepts

Tax Residency

◾ Main purpose: Determines which country can tax your worldwide income
◾ Set by: Tax authorities, based on time spent and personal/economic ties
◾ Directly affects taxes: Yes
◾ Can you have it in multiple countries simultaneously: Sometimes — leading to a dual residency situation
◾ Day counting: Yes, most countries use physical presence thresholds (such as the 183-day rule) as a primary or contributing factor in determining tax residency status.

Domicile (Tax Domicile)

◾ Main purpose: Establishes your permanent legal home and long-term intentions
◾ Set by: Legal interpretation, courts, and tax authorities — not by day-counting
◾ Directly affects taxes: Often — especially inheritance tax, estate planning, and succession
◾ Can you have it in multiple countries: No — you can only have one domicile at a time
◾ Day counting: No, domicile is determined by long-term intention and legal ties, not by counting days in a country.

Residence Permit

◾ Main purpose: Grants legal permission to live in a country
◾ Set by: Immigration authorities
◾ Directly affects taxes: Indirectly — it may make tax residency more likely, but doesn't determine it
◾ Can you have it in multiple countries: Yes — some people hold residence permits in multiple jurisdictions simultaneously
◾ Day counting: Yes, many permits require minimum presence or limit time spent outside the country to maintain validity, though the thresholds are set by immigration authorities rather than tax rules.

Real-Life Scenarios for Expats, Nomads, and Global Mobility

A US Citizen Relocating to the UK

A US citizen moves to London on a Skilled Worker visa. After spending sufficient time in the UK, they qualify as a UK tax resident under the Statutory Residence Test. However, US citizenship-based taxation still applies — meaning they may need to file returns in both countries.

In this case, their residence permit reflects their immigration status, UK tax residency determines their local obligations, and they may remain US-domiciled for estate tax purposes. All three statuses can point to different outcomes simultaneously.

A UK Entrepreneur Working Between London and Miami

A UK-based founder regularly works from Miami but spends fewer than 183 days in the US annually. Under the Substantial Presence Test, they likely avoid becoming a US tax resident. However, any US-source income could still carry tax implications.

Their domicile remains in the UK even while they operate internationally, and double taxation treaty tie-breaker rules — which look at permanent home, center of vital interests, and habitual abode — would confirm UK as the primary taxing jurisdiction.

A Digital Nomad With a Portuguese Residency Visa

A US remote worker obtains a Portuguese Digital Nomad Visa and spends most of the year in Lisbon. They become Portuguese tax residents, while still filing US tax returns as a citizen.

Their domicile likely remains in the US. This scenario is increasingly common and illustrates how fiscal residency, immigration status, and domicile can each point in different directions at the same time.

A Professional Using a UAE Golden Visa

A high-earning professional obtains a UAE Golden Visa, establishing legal residency in a zero-income-tax jurisdiction. To exit UK tax residency under the SRT, they must sever sufficient UK ties and spend fewer than the permitted number of days in the UK each year.

Holding a UAE residency permit alone is not sufficient to become a UAE tax resident or to exit UK tax residency — the day counts and tie-breaker rules under the SRT still apply. This is a common misunderstanding among people restructuring their international lives.

Common Mistakes to Avoid

Assuming a visa automatically creates tax residency. Having a residence permit does not automatically make someone a tax resident. Tax authorities evaluate time spent, economic ties, and personal connections independently.

Confusing citizenship with domicile. These are different legal concepts. A US citizen can become UK-domiciled over time, while a UK citizen abroad may remain UK-domiciled for decades. Citizenship and domicile follow different rules entirely.

Ignoring double taxation treaties. It is possible to become a tax resident in two countries simultaneously. In these cases, tax treaties include tie-breaker rules that determine which country holds primary taxing rights. These rules typically consider permanent home, center of vital interests, habitual abode, and nationality — in that order.

Underestimating the impact of permanent establishment. For founders and directors operating across borders, the concept of permanent establishment can create unexpected corporate tax exposure — separate from any personal tax residency question.

In practice, staying on top of all three statuses starts with accurately tracking your days across jurisdictions — which is harder than it sounds when multiple countries apply different counting rules and overlapping tax years. Flamingo Compliance is a professional iOS app that automates this with jurisdiction-specific trackers, threshold alerts, and detailed reports you can share directly with your tax advisor.

Frequently Asked Questions

Does a residence permit automatically make you a tax resident? No. A residence permit only gives you legal permission to live in a country. Tax residency is determined separately, based on factors such as time spent in the country, work activity, and personal ties. You can hold a permit without becoming a tax resident, and vice versa.

Can you have a domicile in one country and tax residency in another? Yes. This is common among expats and international professionals. For example, someone may live and pay taxes in the UK while remaining legally domiciled in the US — which would affect how inheritance tax is applied to their worldwide estate.

What happens if you become a tax resident in two countries simultaneously? Double tax treaties typically include tie-breaker rules to determine which country has primary taxing rights. These provisions look at your permanent home, center of vital interests, habitual abode, and nationality. The goal is to prevent the same income from being taxed twice — though filing obligations in both countries may still apply.

How do countries determine domicile? Domicile is assessed based on long-term intention, permanent home, family ties, and legal connections — not simply by counting days. Courts and tax authorities look at where you genuinely intend to live permanently, which is a higher and more subjective standard than tax residency.

How do you change your domicile? Changing your domicile requires both physically relocating to a new country and demonstrating a genuine intention to remain there permanently. Courts and tax authorities look at factors such as property ownership, family ties, and whether you've severed meaningful connections with your previous country — not simply how long you've lived abroad. This is a high legal bar, and many long-term expats remain domiciled in their country of origin for years without realising it.

What is the difference between permanent residence and tax residency? Permanent residence is an immigration status — a long-term permit to live in a country. Tax residency is determined by tax authorities based on your time, ties, and activity in a country. You can hold permanent residence without being a tax resident, and you can be a tax resident without permanent residence. The two are legally independent.

Does the 183-day rule apply everywhere? The 183-day rule is a widely used threshold, but it is not universal. Many countries have additional tests based on economic ties, housing, and family connections. The UK's Statutory Residence Test, for example, can classify someone as tax resident well below that threshold.