The Cartao de Cidadao is Portugal's smart-card national identity document, consolidating into one card the former identity card, taxpayer, social security, health and voter registration documents. Its chip supports electronic authentication and qualified electronic signature. A new EU- and ICAO-compliant biometric model began issuance in June 2024.

Chave Movel Digital is a state-certified means of authentication and qualified digital signature that links a person's mobile phone number to their identity document. With a single login it lets holders access public and private portals and sign digital documents. It is free and can be activated by Portuguese citizens and by foreign residents.