QES vs AdES under the EU eIDAS Regulation

Has the equivalent legal effect of a handwritten signature under eIDAS Article 25.

Cannot be denied legal effect or admissibility only because it is electronic or not qualified, but it does not receive automatic handwritten-signature equivalence under Article 25.

Use QES where handwritten-signature equivalence is required; use AdES where the legal need is strong electronic evidence assessed in context.

Requires a qualified certificate for electronic signatures issued by a qualified trust service provider, and the trusted-list record should support that status.

May use certificates and trust services, but AdES status alone is not proof that the certificate is qualified or that the provider has qualified status for that service.

For QES, validate QTSP and qualified-certificate status from trusted-list evidence; for AdES, keep certificate and identity evidence without overstating qualified status.

Requires creation by a qualified electronic signature creation device. Remote QSCD management must be performed as a qualified service by a qualified trust service provider.

Requires creation data that the signatory can use under sole control with a high level of confidence, but Article 26 does not require a QSCD.

QES evidence must include QSCD or remote QSCD support; AdES evidence should focus on signer control and integrity without claiming device qualification.

The validation process must confirm certificate qualification, QTSP issuance, certificate validity at signing, matching validation data, signatory data, pseudonym indication if used, QSCD creation, signed-data integrity, and Article 26 compliance.

The evidence should prove Article 26 requirements and, if the signature is based on a qualified certificate, the separate Article 32a validation conditions for that middle category.

A QES validation report should be retained with trusted-list, certificate, revocation, QSCD, and signed-data-integrity evidence; AdES records should not omit signer identity, signer control, and tamper-detection evidence.

Classify as QES only when the evidence proves AdES requirements, qualified certificate status, QTSP issuance, QSCD creation, and a valid QES validation result.

Classify as AdES when the evidence proves Article 26 requirements but the record does not prove every qualified certificate, QTSP, QSCD, and QES validation condition.

Use the lowest accurate label. Calling an AdES a QES creates a certificate, provider-status, device, and validation-evidence gap.

QES validation is time-sensitive: the record has to prove qualified status at the time of signing, not just at review time.

AdES review focuses on whether the Article 26 conditions were met at signing; there is no QES-only timing layer to prove.

Keep timestamps, revocation evidence, and validation output for QES. For AdES, keep enough evidence to show the Article 26 conditions at the signing moment.

Receives the equivalent legal effect of a handwritten signature.

Stays admissible as evidence, but it does not get handwritten-signature equivalence by itself.

Treat QES as the higher legal-effect label. Treat AdES as the evidence-based option unless a rule specifically asks for qualified status.

A valid QES record normally already contains the proof needed to satisfy the AdES baseline.

An AdES record does not automatically prove the extra qualified certificate and QSCD layers required for QES.

Reuse QES evidence when you only need AdES proof, but do not upgrade an AdES label to QES without the extra qualified-status evidence.

Choose QES when the request or rule calls for handwritten-signature equivalence or when the file must prove qualified status end to end.

Choose AdES when the business or legal need is strong electronic evidence, but qualified-status proof is not required.

Start from the legal requirement, then label the signature at the lowest level that the evidence supports.