Originally Posted by LHR Tim
Just to clarify, UA can only make changes to a travel agent issued ticket AFTER you've flown the first segment.
I wanted to buy up an M ticket to B from LHR-IAH. UA would not touch it with a barge poll (c'mon, I'm giving you more money!). In the end, I did get a sympathic agent at our company TA, who managed the add-collect.
On the return, I just called UA and made changes without a problem.
While it's true they won't touch the routing before departure, if you can get the right agent on the phone, they have ways to collect the money without pissing off the travel agency.
I've bought up an H fare to Y without going thru work's travel agency when they refused to do it. It took the agent about a half hour to do it, but they got it done. The travel agent never balked at it either.