Originally Posted by
Grogs
You can definitely buy up afterwards, but there are catches. AFAIK, you're not actually buying an F ticket, just the right to sit in F on those particular flights. If you have to change flights due to weather or something, you could end up back in coach with little or no refund. The other problem is that there's a lot of variation in those offers. F might cost $200 more at booking, but the buy up (FCM) price might be $500 or could be $100. A cleaner way to do it would be to call in during the first 24 hours and just pay the fare difference to actually be rebooked in F. That's more of a grey area though because they're actually issuing a different ticket than what the company bought. I would call your travel office and make sure they are OK with that before I tried it.
Not true. It's not a F ticket only if you use the seat map and do an a la carte seat upgrade on only one flight to F. If you click the upgrade all segments, it upgrades to an actual F ticket. All phone agents can do is actual upgrades to an actual F ticket. They can't even sell the al a carte seat upgrades.
The big issue is that if OP calls, then DL will have to take control of the ticket. $50 for this. Also means employer TA will no longer be able to make changes to ticket. Thus make sure they're ok with it.