Advanced electronic signature (AdES)
An advanced electronic signature (AdES) is the middle level of signature under the EU's eIDAS Regulation: stronger than a simple signature, without the qualified certificate and device a qualified signature needs.
Updated November 5, 2026 · 1 min read
The four requirements
Article 26 of eIDAS says an advanced electronic signature must:
- be uniquely linked to the signer;
- be capable of identifying the signer;
- be created with signature creation data the signer can, with a high level of confidence, use under their sole control;
- be linked to the signed data so that any later change is detectable.
How it's usually made
Most advanced signatures are certificate-based digital signatures built on public key infrastructure. ETSI standards define the formats: PAdES for PDFs, XAdES for XML and CAdES for other files. For example, a supplier signs an invoice PDF with a certificate on a company smart card, and the PDF reader shows the signature as valid until someone edits the file.
SignMaster doesn't apply certificates to PDFs, so it doesn't claim AdES. It records an audit trail of every step, each signer's consent to sign electronically, and a SHA-256 fingerprint of each file on the certificate of completion.
Questions? Answers.
Is an advanced electronic signature legally binding?
Yes. Like any electronic signature under eIDAS, it can't be denied legal effect just because it's electronic. Its advantage is evidence: it's easier to show who signed and that nothing changed since.
Sources
- Regulation (EU) No 910/2014 (eIDAS), Articles 3, 25 and 26 (EUR-Lex) · eur-lex.europa.eu