The Supreme Court confirmed that an entrepreneur, who listed business appointments in his private diaries, had to keep those diaries.
Information and administration obligation
Interested party operated a tax consultancy in the legal form of sole proprietorship. Therefore, an information and administration obligation rests on him. This means that the entrepreneur is obliged to provide information to the tax authorities, if they request it. And an entrepreneur is also obliged to keep records, which must be kept for at least 7 years.
Entrepreneurs who fail to meet these obligations face reversal of the burden of proof. That means they have to prove that the income tax (or corporate income tax) returns they file are correct and complete. And for that, if the administration obligation is not met, the records cannot be used.
Private diary
These obligations obviously only apply to information relevant to the entrepreneur's taxation. The private diary is, in principle, obviously not. However, in the case decided by the Supreme Court, the entrepreneur also noted business matters in his private diaries. As a result, these diaries also fall under the statutory record-keeping and retention obligation. In these proceedings, the Tax Court succeeded in making it plausible that the tax adviser noted down appointments for providing tax returns for people in the circle of friends in the private diaries and that he received fees for this work (but the Court considered that the private diaries are also relevant if it was not established that fees had been received, for the purpose of checking whether or not fees were received).