The Customs office (Zoll) is responsible for checking the employers. The Customs office is a government authority. Here there is a department for checking companies, which is called the Tax Enforcement Unit for Undeclared Work (“Finanzkontrolle Schwarzarbeit” - FKS). The Tax Enforcement Unit for Undeclared Work checks whether all employees are correctly registered in a company, whether the employer is paying contributions to social insurance, and whether all employees are receiving payment of the minimum wage. If the Tax Enforcement Unit for Undeclared Work receives a tip about a specific company, it is able to check this.