My partner and I are planning a trip from Los Angeles to Istanbul in August. We have miles with United that we would like to use to upgrade coach sets with. It seems that only certain coach fare classes are up-gradable and NONE of them show up on the Turkish reservation site.

Where can I find a place to book using the up-gradable class fares such as M A S H ?

I have read on travel forms that this can be done and they make it seem SOOO easy but never tell you exactly where or how to do it!

Could someone please give me detailed directions on how to do it?

Thank you!