If you make a reservation on NWA.COM, then Northwest has its "Customer First" policy, which essentially gives you until midnight the next day to change your mind and get a full refund. I've used this a couple of times. Once when the rate dropped on a non-refundable less than six hours after I made a reservation (got my money refunded rather than an MCO) and another time when I got brain lock and reserved the wrong day. Realized my problem within an hour and called and changed. One other time I wanted to switch to a different flight so I called. They could have cancelled my reservation but I would then have been inside 14 days and the ensuing ticket I bought would have been more expensive so I stuck with what I had. The ticket will be issued automatically unless you call NW.