Hi all -- new to this forum and hope someone can answer a quick question. I often fly US on ZED-fare tickets, and have purchased upgrade certificates domestically as an OA employee. Sometimes they come up as $20 when the check-in agent puts in my info, sometimes at $40. What is the correct charge for these certificates? Also, what is the charge internationally? Thinking about riding US to TLV.

Thanks so much for your help!

jc