Originally Posted by
lovetotravel
When you purchase your ticket with the credit card or use it to pay taxes on an award ticket, it it automatic, no fee is charged.
EDIT: Yes, you do have to use the card, other wise you will be charged.
Don't believe this is true. The card (credit or debit) should be linked to your OnePass account. When you fly and use that OnePass number as your FF number in the reservation, there should not be a charge. If not, you should be able to simply show the card at the check-in area and avoid the charge.