what constitutes other income generated from rental properties here are some of the most common sources of cash flow not derived directly from rental payments 
in real life a unit will not always be rented for the entire year vacancy costs are the periods between tenants where the owner is not receiving rent because there is a vacancy vacancy costs are forecasts of how long the owner believes his unit will be without a tenant if the owner has managed investment properties for some time this cost may be estimated based upon his her managerial experience or industry data credit costs will occur when a rental unit is occupied and the owner does not receive the agreed upon rental payment the renter has not paid the rent or has not paid it in its entirety as with vacancy costs this amount will be an estimate that may be based on historical data 