This book provides a comprehensive overview of the most important taxes that entrepreneurs and businesses encounter in their daily operations: income tax, corporate tax, local taxes, and value-added tax. The focus is on income taxes, particularly concerning issues of profit determination, accounting, loss offsetting, and loss carryforward. It also addresses significant questions related to non-business income, such as managing directors' remuneration and capital income. In the area of value-added tax, the book emphasizes the essential questions of national and cross-border supply and services.