With the Whistleblower Protection Act (HinSchG), the German legislator has created a universally applicable law for the first time that regulates the obligations and requirements for establishing a whistleblower system or an internal reporting office and reporting channels. The legislator fulfills its obligation under the EU Whistleblower Protection Directive and has implemented it into German law. In particular, companies with typically at least 50 employees are required to establish and operate an internal reporting office and a channel for reporting information about violations. The function of the internal reporting office can be carried out by designated reporting officers. These officers must meet various legal requirements and be appropriately qualified to fulfill the tasks of the internal reporting office. This work provides reporting officers with an overview of the legal requirements of the HinSchG, particularly regarding the internal reporting office, the reporting channel to be maintained, the procedure following the receipt of a report, and the follow-up actions to be taken. It also considers the significant data protection and labor law implications in this context. Practical advice is consistently provided for establishing a whistleblower system, as well as for implementing and complying with the legal requirements.