It depends on what you are communicating to the customer. If you are telling them in general terms how much they could afford to borrow based on their income and other factors, that would not be an application. On the other hand, if you are making a credit decision and informing the customer that you have approved them for a loan up to $X, you have an application. Whether you consider it complete or not, it is still an application. The FDIC has an excellent publication on their web site ("Prequalifications: Applications or Not?") that discusses when prequalifications turn into applications.
CRCM, CAFP, DAD