Advanced vs Qualified Electronic Signature: The Differences That Matter
ESignature Law

Advanced vs Qualified Electronic Signature: The Differences That Matter

DocuSign is AES. Swiss Trust Layer is QES. The difference is not just technical. It determines whether your signed contract holds up in court under Swiss and EU law.

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Philipp Stuppnik· Co-Founder & IP Strategy
·July 9, 2026· 8 min read

When a company describes its product as legally binding or eIDAS-compliant, that phrase covers three very different legal realities. Understanding which type of signature you are using determines what happens when a counterparty contests it in court.

What Advanced Electronic Signature (AES) Means

Under eIDAS Art. 26, an advanced electronic signature must be: (a) uniquely linked to the signatory; (b) capable of identifying the signatory; (c) created using data under the signatory's sole control; and (d) linked to signed data so changes are detectable. DocuSign's standard product satisfies these four conditions. AES is the right choice for many commercial contracts. The legal risk is that AES carries no statutory legal presumption equal to a handwritten signature. If a counterparty disputes authenticity, you must produce supplementary evidence.

What Qualified Electronic Signature (QES) Means

A QES meets all four AES requirements plus two more: it is generated by a Qualified Electronic Signature Creation Device (QESCD), and it is based on a qualified certificate from a QTSP listed on the EU Trusted List. The legal consequence is stated plainly in eIDAS Art. 25(2): a QES has the equivalent legal effect of a handwritten signature. In Switzerland, ZertES Art. 11 provides the same rule. This is a statutory presumption. A counterparty contesting a QES bears the burden of proving it is invalid.

The DocuSign Comparison

DocuSign does offer a QES product, but it requires separate onboarding through a QTSP and is not the default product. The standard DocuSign workflow most users sign up for is AES. Check your account settings to confirm which level you are using before relying on it for contracts that require written form under law. Swiss Trust Layer applies QES by default. See the full DocuSign vs Swiss Trust Layer comparison.

Which Tier Do You Need?

  • Internal approvals, low-value orders — SES or AES is sufficient in most cases.
  • Commercial contracts, NDAs — AES is typically acceptable unless the other party specifies otherwise.
  • Contracts requiring written form under Swiss OR or EU law — QES is required. AES will not satisfy the written form requirement.
  • Cross-border contracts needing EU-wide enforceability — QES provides the strongest path under eIDAS Art. 25(2).

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