Tax residency determines which country has the right to tax your worldwide income. Rules vary but typically consider physical presence (183+ days per calendar year), centre of vital interests (family, property, business activity), or habitual abode.

Tax residency is independent of citizenship and immigration status. Changing tax residency typically requires formal steps including proof of departure and registration in the new country — simply spending fewer than 183 days somewhere does not automatically terminate residency in most jurisdictions.

Incorrect tax residency assumptions are among the most common and costly mistakes made by remote workers.