In the Netherlands it is statutory (based on legal requirements) mandatory for an medium sized or large company to let do an audit of the financial statements.
Companies where any two of the three criteria mentioned after this are applicable for two consecutive years classify as medium sized:
Auditors performing statutory audit engagements in the Netherlands are supervised by the AFM (Authority Financial Markets). Only audit companies with license from the AFM are allowed to perform statutory audits.
The professional body for accountants in the Netherlands is the NBA (Nederlandse Beroepsorganisatie van Accountants – The Netherlands Institute of Chartered Accountants) and all accountants in public practice must belong to this body.