<font face="Verdana, Arial, Helvetica, sans-serif" size="2">Originally posted by NJDavid:
It depends on what type of upgrade you're trying to use.
Mileage upgrades (domestic) are from any fare, as are Elite upgrades.
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Elite upgrades, for instance, aren't allowed with the $99 Prestige pack companion fare cert... although they should be... but thats just my opinion.