I thought that I had booked seat 2-K when I bought my ticket online but apparently I missed some confirmation step. I did not contact the airline or manage my booking because I thought that I had successfully reserved seat 2-K for both my outbound and inbound flights and only discovered that I did not have the seat when I checked in at the airport. I have recently checked the booking of my return flight and searched for my seat reservation for quite a while. I finally found it nested under "services" and not on my main itinerary page. The web page should be improved. I have flown in FC with Thai for many years and never had a problem booking my seat and even finding the location of the seat assignment until this year. I will always double-check my seat reservations in the future and hope to avoid the problem that I had this time Still, the airline should not sell a first class ticket without a seat reservation. I have never had that happen with any other airline, ever.