imagine if you went to see a flat and the landlord asked you for your income details. Would you disclose this to them?
Yes of course , there is no way you can rent a place in Germany,UK, Italy France Spain etc without showing your bank statements or pay slips or Income tax forms.
Why would it be a problem to disclose your income details ?
If one needs a loan from a bank,don't people have to show proof of their income?
Here in Poland I play safe by renting either to friends or friends of friends, or to corporates through an agency
inkrakow i will PM you for details of this agency for corporates, thanks