Business expenses are expenses that are made to acquire, secure and maintain income (Section 9 I EStG). They are tax-deductible on excess income. The income-related expenses are deducted from the income in connection with which they arose. The equivalent in profit income is business expenses. The inducement principle is decisive for the assessment of an expense as advertising expenses.
The expenditure must be objectively related to income generation and subjectively to promote income generation. There are problems of demarcation to the non-deductible costs of private life (§ 12 No. 1 EStG). If the private part is not insignificant (usually greater than 10%), there is no deductibility. The list of advertising expenses in § 9 EStG is not exhaustive.
Advertising expenses include contributions to professional associations, travel expenses, expenses for work equipment and taxes on property. To simplify matters, there are lump sums for certain groups of advertising expenses.