The statutory auditor (organe de révision / Revisionsstelle) is the external control body of Swiss companies required by the Code of Obligations (Articles 727–731a CO) to review annual accounts and report to shareholders. Swiss law provides three distinct regimes based on company size and structure. Ordinary audit (contrôle ordinaire) is mandatory for large companies (two of three thresholds: revenue >CHF 40 million, balance sheet >CHF 20 million, employees >250) and for companies with public debt or consolidated accounts: it must be performed by a licensed auditor under the Swiss Audit Oversight Act (RAG). Restricted review (révision restreinte) is the standard regime for SMEs: a lighter analytical review by a licensed examiner, less intensive than a full audit. Opting-out is available to companies with fewer than 10 FTE employees, provided all shareholders agree in writing.

In Franco-Swiss M&A due diligence, the statutory auditor plays a central role: their affirmation letter (lettre d'affirmation), past audit reports, management letter (points de contrôle), and independence status are analyzed to assess the reliability of the financial statements presented. A recent change of auditor, a qualified audit opinion, or an auditor with documented independence concerns represent material due diligence flags at Hectelion.

The statutory auditor in Switzerland should not be confused with the French commissaire aux comptes (CAC): the Swiss organe de révision does not have the same public interest mandate or the same liability regime. Swiss auditors are not required to report directly to the market authority (FINMA) except for listed companies — their primary accountability is to the company's shareholders.

At Hectelion, we analyze statutory auditor reports and their implications in our due diligences on Swiss targets.