Depending on certain criteria Swiss companies are required to appoint an an accredited Swiss auditor.

Criteria to Avoid an Audit
Companies which employ on average fewer than 10 full time employees during the year can forego the audit of their accounts if the shareholders (or associates) agree to this (art. 727a Swiss Code of Obligations).

Criteria for a Limited Audit
A limited audit is available for companies which during the two previous financial years remained below the threshold for at least two of the three following criteria:
Total balance sheet: CHF 20,000,000
Turnover: CHF 40,000,000
Number of full time employees: 250

Criteria for an Ordinary Audit
An ordinary audit is required for companies which during the two previous financial years exceeded the threshold for at least two of the three following criteria:
Total balance sheet: CHF 20,000,000
Turnover: CHF 40,000,000
Number of full time employees: 250
(Art. 727 s. 2 of the Swiss Code of Obligations)
Additionally, Stock Market listed companies and those who have issued bonds are also required to be audited. An ordinary audit is also required if at least 10% of the shareholders request this.