How do I upgrade my ticket at Thai Airways? by placing a bid online – passengers can visit the booking option to start their bidding.
Thai Airways upgrade policy
The bidding can be placed from the time of booking until 6 hours from departure on the US and Asian flights and before 25.
Read Also - https://cheapestflightsfare.com/blog/how-do-i-upgrade-my-ticket-at-thai-airways/
