A fiduciary firm in Zurich has a client who wants to guarantee a business partner's bank loan. It is Friday evening, the client is travelling, and the signing platform is already open. Before anyone clicks "send", the fiduciary stops. Is a guarantee the kind of contract where an electronic signature is enough? For this one, it is not. Swiss contract form requirements for an electronic signature depend on the contract type, and some types reject it outright.
The short answer
Swiss law does not ask for a special form for most contracts. Where the law does prescribe a form, the type of form decides everything. A qualified electronic signature with a qualified time stamp replaces a handwritten signature, but it does not replace a handwritten text, and it does not replace a public deed. Several well-known contracts need one of those two things.
The rule: no form unless a statute says so
The starting point is Article 11 paragraph 1 of the Code of Obligations (OR). Contracts need a particular form for validity only if the law prescribes one. So a service agreement, a licence or a supply contract can in principle be concluded by email, by handshake or by an electronic signature. If a form is prescribed and not observed, the contract is invalid unless the law says otherwise (paragraph 2). Fedlex publishes federal law in German, French and Italian, and all three versions are equally binding. English translations on the same site are not official, so quote an official version in any file note.
Where electronic signatures work: simple written form
Where the law asks for written form, Article 13 OR requires the signatures of everyone who takes on an obligation, and Article 14 paragraph 2bis puts a qualified electronic signature with a qualified time stamp, under the Federal Act on Electronic Signatures (ZertES), on the same level as a handwritten signature. The same paragraph adds that differing statutory or contractual rules remain reserved. That last sentence is where the exceptions live.
Exception 1: handwritten text, not only a signature
Some statutes ask for more than a signature. Under Article 505 of the Civil Code (ZGB), a holographic will must be written by the testator by hand from beginning to end, including the year, month and day, and signed. A typed document with an electronic signature does not meet that. The suretyship rules in Article 493 OR contain a similar element: for a small guarantee given by a natural person, the maximum amount must be written in the person's own hand in the document.
Exception 2: public deed
The other group needs a public deed, a document made with a notary or other competent official. Three examples read at Fedlex:
Sales contracts over land, and preliminary contracts and contracts on pre-emption, purchase or repurchase rights over land, are valid only with a public deed (Article 216 OR). A contract transferring ownership of land needs one too (Article 657 ZGB). An inheritance contract must take the form of a public will (Article 512 ZGB). A suretyship given by a natural person also needs a public deed, with a statutory exception for small amounts and for certain guarantees to the Confederation or a canton (Article 493 OR). These are formalities carried out before an official under the rules of the place where it happens, not a signature style you can choose in a tool.
A checklist for the fiduciary desk
Before sending anything for e-signature, ask four questions. First, does a statute prescribe a form for this contract type? If not, Article 11 leaves the choice open. Second, if it is written form, is a qualified electronic signature with a qualified time stamp used, and does the statute or the contract reserve something else? Third, does the statute ask for handwriting or a public deed? Then no signing tool will do, and the notary or the pen is the route. Fourth, does the contract itself say what form amendments need? Article 12 OR extends a statutory written-form requirement to amendments, with a narrow exception for supplementary side terms that do not contradict the document.
Where a seal still helps
A seal is not a form. Sealing a document gives it a trusted RFC 3161 timestamp and a cryptographic fingerprint, and a public verification link anyone can open without an account, as described on how it works. That cannot turn an e-signed guarantee into a valid one. It can show which version of a draft, a file note, a power of attorney in preparation or a client instruction existed at a given time. That evidence sits next to the legal form and does not replace it. A seal also does not show who wrote a document, and it does not show the file was unchanged before it was sealed.
Back to Friday evening
The Zurich fiduciary does not send the guarantee for e-signature. The firm tells the client that, as a natural person, the guarantee needs a public deed, books the notary, and seals the agreed draft and the file note so the preparatory trail is dated. Checking a form takes ten minutes. Finding out later that it was wrong can undo the contract itself. The check belongs before the click, not after the dispute.
Seal the preparatory files for your next client matter and use the validator to check any signed PDF you receive.
