it is not about to report the rental income

it is more or less like if landlord wanna claim expenses on his/her rental property, he/she has to provide all the documentation for the deducted expenses.On the other hand, it will be harder for the person who provides service to hide this income even if it is paid by cash. Anyway, it is good for IRS.

But... if you have rental income in cash, why do you bother to claim any expense??!! hehe