A Qualified Electronic Signature (QES) is the only electronic signature type that automatically counts as the legal equivalent of a handwritten signature across the EU, under eIDAS Article 25. It requires a qualified certificate from a supervised trust service provider.
eIDAS (Regulation (EU) No 910/2014) defines three tiers of electronic signature, each with a different evidentiary strength:
Article 25(1) of eIDAS establishes that no electronic signature, at any level, can be denied legal effect solely because it is electronic. That covers SES and AdES too. But Article 25(2) goes further and applies only to QES: a qualified electronic signature “shall have the equivalent legal effect of a handwritten signature.” That equivalence is automatic and applies across all EU member states, without a court having to separately establish it case by case.
With SES and AdES, the burden typically falls on the party relying on the signature to demonstrate its authenticity if it is disputed. With QES, that burden shifts: the signature is presumed valid, and the party disputing it has to prove otherwise.
A QES cannot be self-issued or issued by an ordinary e-signature platform on its own. It requires a Qualified Trust Service Provider, an organisation listed on a member state’s national Trusted List and, in turn, on the EU List of Trusted Lists (LOTL). The QTSP verifies the signer’s identity to a defined standard and issues the qualified certificate the signature is built on.
If a document was signed with a QES, its validity as a handwritten-signature equivalent doesn’t depend on which platform hosted the signing process. Any independent validator checking the signature against the same trust lists should reach the same conclusion, because the legal weight comes from the certificate and the QTSP behind it, not from the platform.