A specialized accountant

This provides you with an additional level of protection, and its mere presence limits the risk of tax audits. It can also advise you on all matters related to rental, even in the most specific cases. 

However, the situation where the use of a specialized accountant is almost mandatory is the LMNP under the real regime. Indeed, in this case, the documents required by the tax administration are substantial - they constitute what is called the tax return package - and the risks of major errors (calculation of depreciations…) are significant.