You Moved — But Did Your Taxes?

Living Abroad for 18 Months – Are You Tax Resident in Two Countries?

A very common belief in international tax is that once a person leaves their home country and lives somewhere else for long enough, their original tax residency simply stops. In practice, tax residency almost never works that way. Moving abroad for a year or even two years usually creates dual tax residency rather than ending it.

Assume a taxpayer who is tax resident in Country X relocates to Country Y for approximately eighteen months. The individual rents accommodation, lives day-to-day in the new country and may even work there or remotely from there. Most people conclude that the person has now become tax resident in Country Y and ceased to be tax resident in Country X. From a legal perspective, however, both countries may still regard the person as tax resident at the same time.

Each country first applies its own domestic legislation independently. Country X typically looks at factors such as ordinary residence, permanent home, family connections, intention to return and economic ties. A temporary absence, even for more than a year, rarely breaks these connections if the person still considers Country X their real home and intends to go back. As a result, Country X continues to treat the individual as tax resident and therefore taxable on worldwide income.

Country Y then applies its own residency rules. These often rely heavily on physical presence or habitual abode. Because the individual now lives there for most of the year, Country Y also classifies the person as tax resident and likewise claims the right to tax worldwide income. At this point it appears that the same person is fully taxable in two jurisdictions on the same income.

This is the stage where many taxpayers believe they will automatically be taxed twice. In reality, this is exactly the situation double tax agreements are designed to resolve.

A tax treaty does not remove residency under domestic law. Instead, it determines which country is treated as the primary residence country for purposes of applying taxing rights. The treaty applies a sequence of tie-breaker tests: where a permanent home exists, where personal and economic relations are closer, where the individual habitually lives, and ultimately nationality or mutual agreement between revenue authorities. After applying these tests, the person becomes treaty-resident in only one country.

The practical effect is significant. The treaty-resident country is allowed to tax worldwide income in the normal way. The other country must restrict its taxation to specific categories of income connected to it, such as employment performed there, property located there, or business profits attributable to a local establishment. What initially looked like two countries taxing everything becomes a coordinated allocation of taxing rights.

The individual therefore remains domestically resident in both countries but is treated as primarily resident in only one of them for treaty purposes. Double taxation is then eliminated through exemptions or foreign tax credits. The system does not depend on how long the person has been abroad, but rather on where their life is regarded as being centered.

The real risk in temporary relocations is not that both countries legally tax the same income without relief. The real risk is that taxpayers assume their obligations in the original country have ended and stop filing returns or claiming treaty protection. When that happens, the treaty cannot operate correctly and double taxation can arise purely as an administrative consequence.

Living abroad for eighteen months is therefore usually not an emigration for tax purposes. It is a period of dual residency managed by a treaty framework. The determining factor is not physical absence, but whether a person has actually shifted the center of their life to a new country on a permanent basis.