EU electronic signature levels (eIDAS): what is the difference between simple, advanced and qualified signatures?
The basic idea of eIDAS
eIDAS is an EU regulation that came into force in 2016. It creates common rules for electronic identification and signatures across all EU countries. An electronic signature cannot be rejected in court simply because it is in electronic form.
SES – Simple Electronic Signature
SES is the simplest signature level. It can be a name typed in an email, a checkbox on a web form or a drawn signature. SES does not require separate identity verification and is sufficient for low-risk situations.
AES – Advanced Electronic Signature
AES requires that the signer is reliably identified. In practice, the signer authenticates using bank credentials, mobile certificate or equivalent method. For most commercial contracts, AES is sufficient.
QES – Qualified Electronic Signature
QES is the strongest level, directly equivalent to a handwritten signature. It requires a certificate issued by an approved trust service provider and a qualified signature creation device.
When is each level sufficient?
For small businesses, choosing the right level depends on the document's risk and value. SES is enough for internal acknowledgements, AES for client contracts and employment agreements, and QES for real estate transactions or official documents.
Practical example
A three-person consulting firm processes 10–15 client contracts monthly. Switching to AES-level electronic signatures saves approximately 2 hours per week and every contract is traceable through the audit trail.