eIDAS vs ZertES: How EU and Swiss Electronic Signature Law Differ
ESignature Law

eIDAS vs ZertES: How EU and Swiss Electronic Signature Law Differ

eIDAS governs electronic signatures in the EU. ZertES governs them in Switzerland. Both use the same three-tier structure, but mutual recognition is not automatic. Here is what that means for cross-border contracts.

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Philipp StuppnikCo-Founder & IP Strategy
July 9, 2026 8 min read

Switzerland is not an EU member state, so eIDAS does not apply as EU law within Switzerland. Instead, Switzerland has its own electronic signature statute: ZertES (Federal Act on Electronic Signatures, SR 943.03). The two frameworks are deliberately aligned in structure, but they are separate legal instruments. A signature that is qualified under one framework is not automatically qualified under the other.

The Frameworks Side by Side

Both eIDAS and ZertES define three signature tiers: Simple, Advanced, and Qualified. The legal definitions are substantively the same. The key difference is which regulatory body accredits the QTSPs, and which trusted list the QTSP must appear on.

  • Under eIDAS: QTSPs are supervised by national bodies in EU member states and listed on the EU Trusted List (EUTL) at eidas.ec.europa.eu/efda/tl-browser/. A QES from any EUTL-listed QTSP carries the Art. 25(2) legal presumption across all EU member states.
  • Under ZertES: QTSPs must be accredited by the Federal Office of Communications (BAKOM) under the ZertES Ordinance (VZertES, SR 943.032). A QES from a BAKOM-accredited QTSP carries the ZertES Art. 11 legal presumption within Switzerland.

Mutual Recognition: The Gap

Switzerland and the EU do not have automatic mutual recognition for qualified electronic signatures. This means a QES from a Swiss BAKOM-accredited QTSP has full legal effect in Switzerland but EU authorities may not automatically recognize it as qualified under eIDAS. Conversely, a QES from an EU EUTL-listed QTSP has full effect across EU member states but Swiss courts apply ZertES standards.

For cross-border contracts between Swiss and EU parties, the safest approach is to use a QTSP with both EUTL listing and ZertES accreditation. Swisscom Trust Services holds both. Swiss Trust Layer uses Swisscom Trust Services as its QTSP partner for exactly this reason.

Key Statutory Differences

  • Timestamp legal presumption: Under eIDAS Art. 41(2), a qualified electronic timestamp has a presumption of accurate time and data integrity. ZertES does not contain an identical provision, though RFC 3161-compliant timestamps from an accredited QTSP carry evidentiary weight in Swiss proceedings.
  • Registered electronic delivery: eIDAS Art. 43 recognizes qualified electronic registered delivery services. ZertES does not have an equivalent at the same level of specificity.

What This Means for Your Contracts

Swiss law contracts: use a QES from a BAKOM-accredited QTSP (ZertES Art. 11). EU law contracts: use a QES from an EUTL-listed QTSP (eIDAS Art. 25(2)). Cross-border EU-Switzerland: use a QTSP with both ZertES accreditation and EUTL listing. Swiss Trust Layer's fiduciary workflow is built on dual-accredited QTSP infrastructure.

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