FF99- 21 days is for MFU-ing a previously booked paper ticket which has to be sent it and reprinted.
Originally Posted by senorbob
I was going to do a one way MFU due to availability, but they insisted that they had to charge the full return upgrade mileage. Then they told me one way upgrades weren't allowed at all, even when it was due to no availability.
This is what the T&Cs say however there was DEFINITLEY an AskBA article that said if award class was not available in one direction you could upgrade one way for half the miles- I found this last time we talked about this issue. However, since the website search was enhanced I can't find it... how annoying

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To be honest, I wasn't conviced they knew 100% what the policy was as I was passed from person to person.
Welcome to the EC 'Help'line... if only we could get Maws every time we called!
As it happened, they contacted inventory (or whatever the department is called) and extra award seats were relased so I got the return trip in J.
You were lucky... they are very tight about even trying this nowadays