Clients loaned son money to purchase a home (not the clients' home).  Everything done correctly so IRS doesn't consider it a gift, i.e., went to title company for closing, promissory note issued, interest rate above the AFR rate set by IRS.  They didn't prepare a 1098 to give to the son nor did they prepare a 1099-INT to give to themselves.  So do I just put the interest they received on Schedule B or do I need to use some other form?  Do I show the son's name as the payer of the mortgage interest on Schedule B?