ZertES Compliance Guide for Swiss Companies 2026

What Is ZertES and Why Swiss Companies Need It Now

Switzerland's Federal Act on Electronic Signatures — ZertES (SR 943.03) — governs the use of qualified electronic signatures and seals in Swiss law. It is the legal framework that grants digital signatures and qualified timestamps the same standing as handwritten signatures under Swiss civil and commercial law.

In 2026, ZertES compliance is no longer optional for many Swiss companies. Public procurement thresholds, FINMA banking regulations, court filing requirements, and healthcare data obligations are converging to demand qualified digital seals on contracts, audit trails, and official records. Companies still relying on simple PDFs or unqualified e-signatures face growing legal exposure — especially when documents are challenged in court.

The Federal Office of Communications (BAKOM) accredits the Qualified Trust Service Providers (QTSPs) that issue ZertES-compliant seals. Only seals from accredited providers — such as Swisscom Trust Services — carry full legal weight under Swiss law.

Who Must Comply with ZertES in Switzerland

ZertES applies broadly across Swiss commerce, but certain sectors face direct statutory obligations:

Public procurement: Under Swiss public procurement law, contracts above the CHF 230,000 federal threshold increasingly require verifiable electronic records. ZertES SR 943.03 Art. 2 defines which entities — federal bodies, cantons, and contracting authorities — must recognise qualified electronic signatures and seals as legally equivalent to wet signatures.

Banking and financial services (FINMA): FINMA requires banks and asset managers to maintain tamper-evident, time-stamped records under the Financial Services Act and its ordinances. A ZertES-qualified seal combined with a qualified timestamp (RFC 3161) creates an immutable audit trail acceptable to FINMA examiners.

Healthcare: Swiss healthcare providers must protect patient records under the Federal Act on the Protection of Health Data. Qualified seals bind records to a cryptographic timestamp, preventing backdating and proving integrity at the moment of signing.

Courts and arbitration: Swiss civil procedure rules accept qualified electronic documents as evidence. A ZertES-qualified seal from a BAKOM-accredited provider reverses the burden of proof — the challenger must disprove authenticity, not the holder prove it.

For any company that signs material contracts, stores regulated records, or submits filings to public authorities, ZertES compliance is the baseline.

ZertES vs eIDAS — The Dual Compliance Advantage

Switzerland is not an EU member state and is therefore not subject to the eIDAS Regulation. The two frameworks run in parallel:

This distinction matters for Swiss companies operating across borders. A contract executed with a Swiss counterparty needs ZertES standing; the same contract with a German or French counterparty benefits from eIDAS recognition. Without dual coverage, companies must manage separate signing processes for domestic and cross-border transactions.

Swisscom Trust Services is one of a small number of QTSPs that hold accreditation under both ZertES (from BAKOM) and eIDAS (as a qualified trust service provider listed on EU member-state trusted lists). A seal issued by Swisscom therefore carries legal weight in Switzerland and across the EU simultaneously — no second signing workflow, no duplicated records, no legal gap at the border.

For Swiss companies with EU customers, suppliers, or regulators, this single-seal dual coverage reduces process overhead and eliminates the compliance ambiguity of using two separate tools. See our eIDAS comparison page for a detailed breakdown of EU requirements.

What a ZertES-Qualified Seal Provides Legally

Under ZertES SR 943.03 Art. 2 and the corresponding provisions of the Swiss Code of Obligations (CO Art. 14), a qualified electronic seal is treated as legally equivalent to a handwritten signature for entities — companies, organisations, and authorities — that use it on their official documents.

Three legal consequences follow immediately:

Legal presumption of integrity. A document sealed with a ZertES-qualified seal is presumed to be authentic and unaltered from the moment of sealing. Courts, auditors, and counterparties do not need additional proof unless they can demonstrate specific grounds to challenge it.

Burden of proof reversal. In a dispute, the party challenging the sealed document — not the company that created it — carries the burden of proving tampering or invalidity. This is a significant litigation advantage: companies with qualified seals enter disputes in a structurally stronger position than those relying on unsigned or simply hashed files.

Court admissibility. Swiss civil courts accept qualified electronic documents as admissible evidence under the Swiss Code of Civil Procedure. The RFC 3161-compliant timestamp embedded at sealing proves the document existed in its current form at a specific point in time — critical for IP disputes, contract dating, and regulatory filings.

How Swiss Trust Layer Delivers ZertES Compliance

Swiss Trust Layer AG integrates directly with Swisscom Trust Services, the leading BAKOM-accredited QTSP in Switzerland. Every seal issued through the platform is a ZertES-qualified organisational seal backed by Swisscom's BAKOM accreditation — not a simple hash or an unqualified timestamp.

Key delivery parameters:

• CHF 5 per document — pay per seal, no minimum commitment
• Under 2 minutes from upload to signed certificate delivery
• Public verification without login at verify.swisstrustlayer.com — any counterparty, court, or regulator can confirm seal validity without creating an account
• Dual ZertES + eIDAS coverage — one seal, two jurisdictions, one workflow
• Tamper-evident certificate — cryptographic proof of document state at sealing, suitable for FINMA audits, court filing, and procurement submissions

The platform handles the QTSP integration, certificate issuance, and verification infrastructure. Your legal and compliance teams interact with a clean upload-and-seal interface; the cryptographic complexity is fully managed.

Visit the ZertES product page for a full feature breakdown, or read our qualified timestamp explainer to understand how RFC 3161 timestamps anchor your seals to a legally verifiable moment in time.

Step-by-Step: Get Your First ZertES-Qualified Seal

Getting ZertES-compliant seals into your document workflow takes under ten minutes:

1. Upload your document — PDF, DOCX, or any file format via the Swiss Trust Layer portal or API
2. Apply a qualified seal — the platform requests a ZertES-qualified seal from Swisscom Trust Services on your behalf; no separate QTSP relationship needed
3. Receive your signed certificate — a sealed PDF with embedded cryptographic signature and RFC 3161 timestamp is returned within 2 minutes
4. Verify at any time — share the verify link with counterparties, courts, or regulators; verification is public and requires no login
5. Store in your system — the sealed document can be stored in any DMS, contract repository, or cloud storage

Your compliance team gains an audit trail that holds up in Swiss courts and before FINMA — without changing your existing document management system.

Start Sealing ZertES-Compliant Documents Today

Swiss Trust Layer AG provides ZertES-qualified document seals backed by Swisscom Trust Services BAKOM accreditation, at CHF 5 per document with no minimum commitment.

For Swiss companies with compliance obligations in public procurement, financial services, healthcare, or litigation-adjacent workflows, ZertES qualification is the lowest-risk path to legally defensible digital records.

Explore the ZertES product page for technical specifications, or register your company account and issue your qualified seals today.