KRFACTS AUSGABE MÄRZ 2026 Electronic signatures and digital contracts: Legal basis and practical information

Digital business processes now determine contract processing in almost all industries. Electronic signatures are a key tool for efficiency and flexibility, but the legal framework is complex and raises practical questions. The following article provides an overview of the legal requirements and practical obstacles involved in using electronic signatures in Switzerland.

Electronic signatures: What types are there?

The Federal Act on Electronic Signatures (ZertES) distinguishes between four types with different requirements in terms of security and legal effect:

• Simple electronic signature (EES): This includes, for example, attached image files with signatures or confirmation by clicking on checkboxes (‘I agree’). The EES does not provide secure proof of identity and is therefore not legally sufficient for many transactions with formal requirements.
• Advanced electronic signature (AES): The AES supplements the EES with additional security features, usually through two-factor authentication. This makes identity and authenticity easier to verify. However, it does not achieve legal equivalence with a handwritten signature.
• Regulated electronic signature (RES): The RES is based on the AES and additionally integrates a qualified electronic certificate from a recognised provider.
• Qualified electronic signature (QES): The QES is considered the strongest electronic signature in legal terms and, if created by a certified provider (currently only Swisscom Sign, DigiCert or SwissSign for private individuals), is completely equivalent to a handwritten signature in accordance with Art. 14 para. 2bis OR. The providers guarantee both the identity of the signatory and the integrity of the document. The widely used electronic signature from DocuSign is not a QES in Switzerland and is therefore not equivalent to a handwritten signature.

Principle: No formal requirements for concluding contracts

In Switzerland, freedom of contract applies, which also includes freedom of form. Accordingly, most contracts are valid even without a written signature, as they could also be concluded verbally. In such cases, any signature is sufficient. However, the format may play a role if the identity of the signatory is questioned, e.g. in a subsequent legal proceeding.

Exception 1: The legally prescribed written form

The law expressly stipulates the written form for certain legal transactions; examples include the termination of rental agreements (Art. 266l OR), apprenticeship agreements (Art. 344a OR) or the assignment of claims (Art. 165 OR). In these cases, either a handwritten signature or a signature with a QES is mandatory. EES or FES are not sufficient. Failure to comply with the formal requirements will result in the entire legal transaction being null and void.

Exception 2: The arbitrary written form

Many contracts contain a written form clause. Such contractual clauses stipulate that all amendments to the contract must be made in writing. Without a more detailed description of what exactly is meant by ‘written form’, it is assumed that a handwritten signature or a QES must be provided in order to bind the contracting parties (cf. Art. 16 para. 2 OR). If the parties wish to allow other forms of written communication, such as FES, it is advisable to specify this explicitly.

Special challenges in international contracts

Additional requirements apply to international contracts: while QESs are legally valid in Switzerland under Swiss SertES, EU countries only recognise signatures that are certified in accordance with the eIDAS Regulation. For crossborder contracts, it is therefore essential to carefully examine the respective signature standards.

Archiving without media discontinuity

The originality and verifiability of electronically signed documents depend on their correct archiving. Digitally signed documents should always be archived digitally and not as printouts, as only the digital documents are originals. In the case of handwritten signatures, only the paper originals are legally relevant; scanned versions are only considered copies and cannot be used as evidence in the event of a dispute. If a document is signed digitally by one party and by hand by the other, both originals must be retained.