Qualified electronic signatures are the most recommended option, as their validity is recognized for the vast majority of documents
2024/05/24
What types of digital signatures exist?
Under the eIDAS Regulation, there are three levels:
- Simple Electronic Signature – The most basic and least secure (for example, an email footer).
- Advanced Electronic Signature (AES) – Offers greater security; it is uniquely linked to the signatory and allows any subsequent change to the document to be detected.
- Qualified Electronic Signature (QES) – The highest level of security and the only type that has full legal equivalence to a handwritten signature under Portuguese and EU law.
What is Chave Móvel Digital (CMD)?
The Chave Móvel Digital (Digital Mobile Key) is a simplified authentication and digital signature system certified by the Portuguese State. When used to sign documents, it operates as a Qualified Electronic Signature.
Key benefits
- Full probative value – Under Article 376 of the Civil Code, a document signed with a QES has the same evidentiary value as a handwritten private document.
- EU‑wide recognition – Thanks to the eIDAS Regulation, qualified signatures issued in Portugal are recognized in all EU Member States.
- Versatility – Suitable for any document that does not legally require a public deed (for example, lease agreements and private contracts).
How to activate it?
Citizens can activate CMD online using their Citizen Card or Tax Portal (Finanças) credentials, or in person at designated government service counters.
Ana Catarina Dias | [email protected]
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