SES, AES, and QES — what the levels mean
A plain-language guide to Simple, Advanced, and Qualified electronic signatures — and when each is appropriate.
Electronic signatures are not one-size-fits-all. Under eIDAS (and aligned UK practice), you’ll hear three levels: SES, AES, and QES.
SES (Simple Electronic Signature) is the everyday click-to-sign or typed signature with a clear audit trail. It’s widely used for commercial agreements where the law does not demand a higher form.
AES (Advanced Electronic Signature) ties the signature more tightly to the signer — for example via bank-backed identity verification such as OneID in the UK — and is often used for stronger assurance workflows including many deed and witnessing scenarios.
QES (Qualified Electronic Signature) is created with a qualified certificate from a Qualified Trust Service Provider. Under eIDAS it has the equivalent legal effect of a handwritten signature. Ireland and many EU regulated instruments rely on QES for certain deeds and filings.
Touch2Sign supports all three levels and routes signers according to country and document type. Choosing the right level remains your legal responsibility — we don’t give legal advice, but we do make the technical path clear.