The most important points at a glance
The works contract under Swiss law is generally informal: legally, a signature is often not required for conclusion — even a verbal agreement or an e-mail can establish a valid contract. The choice between EES, FES and QES is therefore primarily a question of evidential value, not validity. Practically: FES is the sensible standard for the entire works contract dossier, QES is only needed where a written form is required.
This is the crux: form is rarely required for the contracts themselves, but for ancillary agreements and addenda. If a contract clause requires "written form" for addenda, QES or a handwritten signature (art. 16 OR) applies; the same applies by law to e.g. the assignment of defect rights (art. 165 OR). And on site, a question arises that no signature level can answer: who was allowed to formally approve the addendum?
What prerequisites does digital signing of a works contract require?
First clarify the form: is form freedom, legal written form, or contractual written form clause applicable? Then determine and regulate the appropriate signature level, and who may bind sign contracts and addenda. For builders, architects and trades, this is central because disputes usually arise not with the original contract but with addenda, site reports and defect notices.
| Signature quality | Typical use in the works contract context | Practical classification |
|---|---|---|
| EES | Informal routine: small orders, receipt confirmations, internal approvals | Legally valid with form freedom, but low evidentiary value |
| FES | Standard for works contracts, addenda, acceptance protocols and defect notices | Identity and document integrity are provable |
| QES | Legal or contractual written form, e.g. assignments | Only level equal to handwritten signature |
How does the signing of PDFs in the correct order work?
- Check the form of the document: informal, contractual written form clause, or statutory written form.
- Set the signature level — FES as standard, QES for written form.
- Define approval roles and amount limits for addenda.
- Add signatories in the correct order and have them sign.
- Prove delivery of time-bound declarations and archive the signed original electronically.
From experience, the signature level does not solve the authorization problem. A technically flawlessly signed addendum is not binding if the signatory was not actually authorized to approve it. This has been confirmed by the Federal Supreme Court in several works contract cases. The clarification of what a signature on the governance report means belongs on the report form itself, not only in the contract.
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What errors slow down the process?
- Addenda are signed without checking the contract’s written form clause.
- Construction management approves addenda prices without explicit power of attorney.
- Governance reports do not specify what the signature means: service confirmation or addendum approval.
- Defect notices are sent without proof of receipt — despite the 60-day limit.
- The signed original is printed instead of being archived electronically.
Important in practice
The most common misconception is that QES is automatically the safer choice. For documents with no prescribed form, it is of little value without proper authorizations. And where the law requires public notary for certain acts, such as guarantees by individuals, QES does not replace that. Securities can be fully digitally processed as informal guarantees (Art. 111 OR).
Do it yourself or use a signing platform?
For simple single cases, a lean process often suffices. Once addenda, multiple participants and deadlines come into play, a platform like actaSIGN® from axelity ag is worthwhile. It enforces the required signature level by document type—from EES to QES—with approval roles, rather than hoping for discipline on site.
We accelerate your signing and approval processes with our Swiss all-inclusive signing platform actaSIGN® and free you from paper.
When is digital signing particularly worthwhile in a works contract?
Mostly where many addenda, reports and time-bound declarations arise. Since the new defect rules in 2026, every day counts: handling defect notices digitally, with substantiation and proof of access, secures defect rights — and reduces media breaks in daily life.
Frequently asked questions
Does a building contract need a QES?
What about addenda?
Is a signature on a tablet on site enough?
What changes with the new defect rules since 2026?
What is the biggest advantage for SMEs with little prior knowledge?
For works contracts, the best path is often not the most spectacular but the neatest. If you set the signature quality in advance and structure the process in a clear sequence, the digital signature becomes a facilitator rather than an obstacle. By addressing this directly in the process, you save time and keep control.
The full analysis with document overview, sample clauses and jurisprudence can be found in the actaSIGN blog. This article is general information and not legal advice for individual cases.
Digitale Unterschrift für Werkverträge aufsetzen
axelity ag, Sargans