Unless you reside in Portugal for 183 days of the year or more, you will not be taxed on your worldwide income. As a non-tax resident, you only need to pay tax in Portugal if you earn any income in Portugal, for example, a rental return from your property. If you do choose to reside in Portugal, there is a favourable Non-Habitual Residency (NHR) program. This grants certain tax exemptions for overseas income tax for the first 10 years of residence.