Written with people moving from Turkey in mind. The Portuguese rules still apply more broadly.
Proof of Accommodation for Visa
You must prove where you will live in Portugal. The most secure option is a 12-month registered rental contract. Short-term Airbnb bookings or hotel reservations are frequently rejected by the Ankara consulate.
Alternatively, a "Termo de Responsabilidade" (invitation letter) from a Portuguese resident hosting you can work, but it must be notarized and accompanied by their ID and proof of housing ownership.