What Is a Statutory Audit in Switzerland? A Guide for SMEs and Startups

A statutory audit is the independent check of your company’s annual accounts required under Swiss law. But not every company needs one, and many can avoid it entirely. What applies to your company depends mainly on its size and structure.

This article explains what a statutory audit involves, who has to get one, and the difference between an ordinary and a limited audit. We’ll also look at when small companies can skip the audit entirely, what changed under the law in 2025, who’s allowed to act as your auditor, and how to keep the process efficient.

What is a statutory audit in Switzerland?

A statutory audit is the independent examination of a company’s annual financial statements by a licensed audit body (Revisionsstelle). Its purpose is to give shareholders, creditors, and other stakeholders reasonable assurance that the accounts present a reliable picture of the company’s position. Under Art. 727 and following of the Swiss Code of Obligations (CO), this framework is mandatory for certain companies.

The audit covers the balance sheet, the income statement, and the notes to the accounts. The auditor checks that these comply with Swiss accounting law and, in an ordinary audit, that adequate internal controls exist.

Your fiduciary or accountant prepares the books and financial statements, while the audit body reviews them independently. How strictly those roles must be separated depends on the audit type, which we cover below.

Who is required to have an audit in Switzerland?

The obligation depends on a company’s size and structure, not on its legal form. Corporations such as the AG, GmbH, and cooperative must have their annual accounts audited unless they qualify for an exemption. Associations and foundations also have audit obligations, though their rules follow a separate framework. By contrast, sole proprietorships and partnerships are generally not subject to a statutory audit.

For companies that do fall under the rules, there are three possible outcomes: an ordinary audit, a limited audit, or a full waiver (opting-out).

A company must undergo an ordinary audit (ordentliche Revision) if it exceeds two of the following three thresholds in two consecutive financial years, based on the reporting year and the year immediately before it, per the Federal Audit Oversight Authority (RAB):

• Balance sheet total above CHF 20 million
• Turnover above CHF 40 million
• More than 250 full-time equivalents on annual average

Certain types of companies always need an ordinary audit regardless of size: publicly traded companies, companies required to prepare consolidated accounts, and companies that contribute at least 20% of the assets or turnover of such a group. In addition, shareholders representing at least 10% of the share capital can demand an ordinary audit even where a limited audit would otherwise suffice. This last option is known as opting-up, and it is separate from opting-out.

Companies that stay below the ordinary-audit thresholds fall under the limited audit by default, unless they qualify to opt out entirely. For a full breakdown of the two audit types, see our comparison of the ordinary and limited audit.

What is the difference between an ordinary and a limited audit?

An ordinary audit is comprehensive and provides positive assurance, meaning the auditor actively confirms the accounts are correct. A limited audit (eingeschränkte Revision) is narrower, relies mainly on management inquiries and analytical procedures, and provides negative assurance, meaning the auditor confirms only that nothing came to their attention suggesting the accounts are wrong. Most Swiss SMEs fall under the limited audit.

An ordinary audit also requires more from the auditor. It requires the auditor to assess the company’s internal control system (ICS) and can only be undertaken by a licensed audit expert, so it takes more time and costs more. A limited audit involves fewer procedures, more relaxed independence requirements, and a faster turnaround.

The choice is not left to the company. Size and structure decide which audit applies, using the thresholds above. We cover assurance levels, procedures, and reporting differences in detail in the ordinary versus limited audit comparison.

Can you avoid the audit? Opting-out for small companies

A company can waive the limited audit, a step called opting-out, if it has no more than 10 full-time equivalents on annual average, has not crossed the thresholds that would trigger a mandatory ordinary audit, and all shareholders or members consent. The waiver is then entered in the commercial register under Art. 727a CO. This makes opting-out the default route for many startups and small owner-run companies: according to market data from auditorstats.ch, the share of potentially audit-obligated Swiss companies that actually have an audit body fell from 57% at the end of 2007 to just 16% by the end of 2024.

A significant change took effect on 1 January 2025. Under the Federal Act on Combating Abusive Bankruptcy, retroactive opting-out is no longer possible. A waiver now applies only to future financial years and must be filed with the commercial register before that year begins, under Art. 727a CO. The last approved annual accounts must accompany the filing.

The effect on the market was immediate: registered opting-outs fell by 86% in 2025, from 2,154 to 311, and the number of audit mandates rose for the first time since 2008. Part of this is a timing effect, since waivers decided in 2025 only take effect from 2026, but even counting the roughly 1,300 opt-outs already filed for 2026, activity remains about a quarter below the previous year’s level.

In practice, this removes a route companies previously used. Before 2025, a company could declare a waiver after its financial year had already closed, sometimes after a difficult audit. That option is gone. Opting-out at the point of incorporation, however, remains available, so a new company can start without an audit body from day one if the conditions are met. This is the norm rather than the exception: in 2024, 99% of newly founded GmbHs and 92% of new AGs waived the audit at incorporation.

Deciding whether to opt out is not always obvious. Banks, investors, and some business partners may still expect audited accounts even when the law does not require them. Nexova advises founders on whether a waiver serves their interests and handles the commercial register filing where it does.

Who can act as your audit body?

The audit body (Revisionsstelle) must be independent of the company and licensed by the RAB. A limited audit requires a licensed auditor (zugelassener Revisor), while an ordinary audit requires the higher qualification of a licensed audit expert (zugelassener Revisionsexperte). The register of licensed providers is public.

Independence rules set clear limits on who can do the work. For an ordinary audit, the audit body may not take part in the company’s bookkeeping at all. For a limited audit, the auditor may assist with bookkeeping or provide other services only where safeguards rule out any risk of the firm reviewing its own work. As a result, the firm that keeps your books usually cannot also serve as your statutory auditor without a proper separation of roles.

Nexova handles this in practice by keeping the two roles cleanly separated. Nexova prepares your accounts so they are audit-ready and works with an independent, established audit firm for the audit itself, giving you a single, coordinated process.

How can you keep the audit efficient and affordable?

The single biggest cost driver is the state of your bookkeeping. Clean, complete, and well-documented accounts mean fewer auditor hours, fewer follow-up questions, and a lower final fee. Disorganised records have the opposite effect.

As a rough estimate, a limited audit for a straightforward SME typically falls in the range of CHF 3,000 to 12,000, though the figure varies with the quality of the records and the complexity of the business. We break down the drivers in detail in our guide to audit costs in Switzerland. Nexova keeps client accounts organised and up to date year-round, which reduces the hours an auditor needs and lowers the final fee.

Glossary: Key audit terms at a glance

• Revisionsstelle (audit body): the independent, licensed party that examines the annual accounts.
• RAB (Federal Audit Oversight Authority): the state body that licenses and supervises auditors.
• Zugelassener Revisor (licensed auditor): qualified to lead a limited audit.
• Revisionsexperte (licensed audit expert): qualified to lead an ordinary audit; the higher of the two licenses.
• Ordentliche Revision (ordinary audit): the comprehensive audit that gives positive assurance.
• Eingeschränkte Revision (limited audit): the lighter audit that gives negative assurance.
• Internal control system (internes Kontrollsystem, ICS): the set of controls a company runs to ensure reliable reporting; reviewed in an ordinary audit.
• Opting-out: waiving the limited audit entirely.
• Opting-up: voluntarily choosing, or being required by qualifying shareholders, to undergo an ordinary audit.
• Opting-in: returning to a limited audit after previously opting-out.
• Organisationsmangel (organizational deficiency): the legal shortfall that arises when a company lacks a legally required body, such as an audit body.
• Handelsregister (commercial register): where audit-related filings, such as opt-out waivers and audit body appointments, are recorded.