Let me share my experience using an Elite Plus Upgrade Voucher (EPUV) on my January 4th IST-SEA flight.

23 hours before departure, a seat became available in the Business Class cabin, which had previously shown as full. I tried to upgrade using my EPUV via the Android app, but after five attempts, I kept receiving the message: "We are sorry to inform you that we are unable to process your transaction at the moment." The error occurred every time I tried. However, when I checked the mileage upgrade option, I saw that I could upgrade for 65,000 miles.

I called the TK Call Center, but they were also unable to process the upgrade with the voucher. To avoid losing the seat, I proceeded with the mileage upgrade.

Right after, I submitted a feedback request to TK, explaining the technical issue and asking for my miles to be refunded in exchange for using my unused EPUV.

A few hours later, while at IST Airport to see off a passenger, I visited the TK ticketing office. The TGS agent attempted the upgrade but was unsuccessful. A TK supervisor stepped in, made a few calls, and proposed a solution: since canceling the mileage upgrade and retrying with an EPUV risked losing the seat, they would manually apply the EPUV after the flight and refund my miles.

I requested written confirmation, but the supervisor explained that it wasn’t possible. However, she personally assured me that she would follow up and even showed me TK’s internal IT correspondence on her screen, which convinced me.

I took my Business Class flight, and three days later, my 65,000 miles were refunded, and one EPUV was deducted from my account.


A screenshot of my mileage statement from the relevant date.