What Taxation for a Furnished Rental?
Edited
As soon as you rent out a secondary residence, even if only for a few weeks a year, the rents collected must be declared and then taxed under income tax.
Since vacation rentals are necessarily furnished, the rents must be declared in the category of industrial and commercial profits ("BIC"), as with long-term furnished rentals.
Remember to deduct from your annual income the charges related to the rental, such as management fees, for example.