No fee for the VDB free vouchers. I recommend that you book the ticket online and hold it, then call Reservations and tell them you will be using the voucher. Since you need to mail it in, or ticket within 24 hours, you can ticket it at the airport. I have been able to use VDB vouchers for friends and family at the airport, but the voucher was in my name all but one time. Never had a problem with the ticket agent at ORD. Good Luck.