May I let my apartment to holidaymakers, and what has to be registered?

Yes, and you may do so as a private individual without registering a business. Register the property before your first listing: guest rooms and guest apartments in class B have not required categorisation since 2020, only registration. You file a declaration under Art. 129a of the Tourism Act with the mayor of your municipality and receive a registration number within seven days; the municipality enters the property in the national register itself. You then create a profile in the national tourist information system and report every arrival and departure within 24 hours. You also register with the municipality for the tourist tax, whose rate varies by municipality and category.