Instructions for Signing with the Digital Mobile Key (Chave Móvel Digital — Assinatura Digital)

This article outlines the process for adding a digital signature on a power of attorney using the Digital Mobile Key (Chave Móvel Digital) and the Citizen Card. This method is valid and secure, allowing you to avoid additional procedures of legalization and apostilles. The steps below will guide you through this process.

1. Access the Portal
   1. Go to the website: https://www.autenticacao.gov.pt
2. Log In
   1. Click on ‘Autenticar-se’.
   2. Choose the "Chave Móvel Digital" option.
3. Enter Your Details
   1. Enter your mobile number and the PIN of the Digital Mobile Key.
   2. Confirm the code sent by SMS to your mobile phone.
4. Sign Documents
   1. Go to the ‘Assinatura de Documentos’ section.
   2. Upload the power of attorney attached to this email.
   3. Follow the instructions to apply your digital signature.
5. Complete the Signature
   1. Verify all details are correct and complete the process.

Advantages of Digital Signature

Legal Validity: The digital signature via the Digital Mobile Key is legally valid in Portugal.

Speed and Convenience: Eliminates the need for travel and reduces processing time.

Security: Ensures the authenticity and integrity of the document using.