Dual Residency and Tax Treaties

Key Takeaways

Dual residency occurs when two countries both consider you a tax resident under their domestic laws.
Tax treaties contain tie-breaker rules that determine which country is your primary tax residence for treaty purposes.
The tie-breaker follows a hierarchy: permanent home, then centre of vital interests, then habitual abode, then nationality, and finally mutual agreement.
Resolving dual residency correctly is essential — getting it wrong can mean paying tax in both countries without adequate relief.
Even after the tie-breaker resolves your residency, you may still owe tax in both countries on specific types of income.

How Dual Residency Happens

Each country has its own rules for determining tax residency. These rules do not always align. Common dual residency scenarios include:

Moving between countries mid-year: You move from the UK to the Netherlands in June. The UK considers you a resident for the part-year period. The Netherlands considers you a resident from your arrival date. For the overlap period, both countries claim you.

Split life between two countries: You have a home in both Belgium and the Netherlands, spend significant time in both, and work in both. Each country's domestic law may treat you as a resident.

Different residency tests: The US taxes based on citizenship (all US citizens are tax residents regardless of where they live). The Netherlands uses the facts and circumstances test. A US citizen living in Amsterdam is a tax resident of both countries.

Good to know

Dual residency is more common than people think. It does not only happen during moves — it can persist for years if you maintain strong ties to two countries. The important thing is to identify the situation and resolve it correctly using the applicable tax treaty.

The Tie-Breaker Rules

When a tax treaty exists between the two countries, Article 4 of the treaty contains tie-breaker rules to assign you to one country for treaty purposes. These rules are applied in order — you stop as soon as one rule gives a clear answer.

Step 1: Permanent Home (Duurzaam Tehuis)

Question: In which country do you have a permanent home available to you?

If you have a permanent home in only one country → you are a resident of that country
If you have a permanent home in both countries → move to Step 2
If you have a permanent home in neither country → move to Step 2

"Permanent home" means a home that is continuously available to you — owned or rented, furnished and maintained. A hotel room is not a permanent home. A house you own but have rented out to tenants is not available to you.

Step 2: Centre of Vital Interests

Question: With which country are your personal and economic relations closer?

This looks at:

Personal ties: Where does your family (spouse, children) live? Where are your social connections?
Economic ties: Where is your primary employment? Where are your investments? Where do you conduct business?

If one country clearly has the stronger ties → you are a resident of that country. If it is too close to call → move to Step 3.

Tip

Courts have found that personal ties often outweigh economic ties when determining the centre of vital interests. If your family lives in the Netherlands but your business is in Germany, the Netherlands typically wins — because personal relationships are considered more fundamental to where you "really" live.

Step 3: Habitual Abode

Question: In which country do you habitually live?

This is essentially a day-count test. If you spend more time in one country than the other over a representative period, that country wins.

The period assessed is usually the full tax year, but courts may look at a longer pattern if one year is unusual.

Step 4: Nationality

Question: Of which country are you a national (citizen)?

If Steps 1–3 have not resolved the issue and you hold the nationality of one of the treaty countries, you are assigned to that country.

If you hold nationality of both countries, or neither, → move to Step 5.

Step 5: Mutual Agreement Procedure (MAP)

If none of the above steps resolve the tie, the tax authorities of both countries must negotiate and agree on which country you are a resident of. This is rare and slow — it can take years.

A Worked Example

Lucia holds Italian nationality. She moved to the Netherlands in 2024 for work. In 2026:

She rents an apartment in Amsterdam (permanent home in NL)
She still owns her apartment in Milan, which she has not rented out (permanent home in Italy)
She works full-time for a Dutch employer in Amsterdam
Her husband and two children moved with her to Amsterdam
Her parents live in Milan
She spends 300 days in the Netherlands and 50 days in Italy

Applying the tie-breaker:

Permanent home: She has a permanent home in both countries → inconclusive, move to Step 2
Centre of vital interests: Her husband and children are in the Netherlands. Her primary employment is in the Netherlands. Her daily life is in Amsterdam. Italy has her parents and her property. Overall, the Netherlands has the stronger personal and economic ties → Netherlands wins

Lucia is a Dutch tax resident for treaty purposes. Italy must provide relief on any Italian-source income, following the Italy-Netherlands tax treaty.

What "Treaty Resident" Means in Practice

Once the tie-breaker assigns you to one country, the consequences are:

Aspect	Treaty Residence Country (NL)	Other Country (Italy, in example)
General tax obligation	Worldwide income	Only source-country income
Tax credits and deductions	Full entitlement	Limited (varies by country)
Treaty benefits	Available as "resident"	Available as "non-resident"
Social security	Depends on applicable regulation (often EU Regulation 883/2004)	May differ from tax residency

Warning

Tax treaty residency and social security residency are determined by different rules. You can be a Dutch tax resident under the treaty but pay social security in another country under EU Regulation 883/2004. These are separate systems — do not assume one follows the other.

Dual Residency Without a Treaty

If there is no tax treaty between the Netherlands and the other country, there are no tie-breaker rules. Both countries may consider you a full tax resident simultaneously.

In this case:

The Netherlands taxes your worldwide income under domestic law
The other country also taxes you under its domestic law
The Netherlands may provide unilateral relief under the Besluit voorkoming dubbele belasting, but this relief may be less generous than treaty-based relief
You may face genuine double taxation on some types of income

This situation is uncommon (the Netherlands has treaties with most countries) but can arise with certain nations. Professional advice is strongly recommended.

Special Cases

US Citizens in the Netherlands

The US-Netherlands tax treaty has a special provision acknowledging that US citizens are always US tax residents. The treaty tie-breaker can assign you to the Netherlands, but the US retains the right to tax its citizens on worldwide income. The treaty prevents double taxation through credits and exemptions, but the interaction is complex.

Moving to the Netherlands Mid-Year

When you arrive in the Netherlands during the tax year:

Your previous country may consider you a resident for the full year or the part-year
The Netherlands typically considers you a resident from your arrival date
The treaty tie-breaker resolves which country is primary for the overlap period (if any)
Your Dutch tax return covers only the period of Dutch residency, but the rates are based on annualized income

EU/EEA Cross-Border Workers

Workers who live in one EU country and work in another often face dual residency issues. The relevant treaty usually resolves this, but practical complications include:

Different tax years or filing deadlines
Different definitions of taxable income
Currency conversion for non-eurozone countries
Coordination of social security (under EU Regulation 883/2004)

Common Mistakes

Ignoring dual residency — If you have a home and ties in two countries, you may be a dual resident without realizing it. This can lead to unexpected tax bills.
Applying the tie-breaker rules in the wrong order — The hierarchy is strict. You cannot skip to "nationality" without first assessing permanent home and centre of vital interests.
Confusing tax residency with social security — These are separate regimes with different rules. Being a tax resident of the Netherlands does not automatically mean you pay Dutch social security.
Not filing in both countries — Even after the tie-breaker assigns you to one country, you may still need to file a (non-resident) return in the other country for source-country income.
Assuming the tie-breaker resolves everything — The tie-breaker determines which country is your "primary" residence for the treaty. But you may still owe tax in both countries on specific income types (e.g., real estate income is always taxable where the property is located).