Fiscal Residency — Residência Fiscal

Portuguese fiscal residency (residência fiscal em Portugal) is the legal status that makes an individual subject to IRS on their worldwide income. Residency is established primarily by the 183-day rule (spending 183+ days in Portugal in a calendar year) or by having a habitual residence in Portugal on 31 December. Tax residents must register their Portuguese address with AT. Once resident, they must file an annual Modelo 3 return covering all worldwide income. Fiscal residency is a prerequisite for accessing special regimes (IFICI, IRS Jovem); it cannot be claimed retroactively. When establishing or breaking residency, taxpayers must ensure their departure from a previous country of residence is formally documented — failure to properly exit another country's tax system can create dual residency and double taxation risk.