Can you upgrade seats on Thai Airways?

Yes, you can upgrade your seat on Thai Airways that can be done by the manage booking option which is available on the official site. You can not only upgrade our seats but also make changes just after the purchase of your ticket. When you upgrade your sweat there might be some extra fare that you have to pay to get the benefit. It also depends upon the type of booking you have if your booking allows you to make the changes then you can do that changes. Here is the step-through through which you can upgrade your seat

Visit the official page of Thai Airways by the web browser or by the mobile application.

On the homepage, you have an option for my booking select that option, 

Now, you have to enter the Thai booking reference and the last name of the passenger then hit on to find the booking

On the new page, you have the detail of your booking and in the dashboard, there is a seat option select that,

Now, choose the seat option and if the fare extends from the original then pay the remaining amount,

When the payment is completed you have to upgrade your seat,

In this way, you can Upgrade Thai Airways flight seats but having any kind of issue then you may contact the concerned authority of Thai Airways. Thai Airways provide customer service in various departments such as call and online chat and also through social media you can state your issue. To get in contact with the customer service go to the contact us option that is on the officiant site and after that select, your region and you have the details of customer service.