just checked my flight number, from UK is not same as my arrival flight number! So would probably be the country I transit through as the flight originated there. Not at all sure. Lol. I think I'll stick with Heathrow as that's where I start my flights.
Others mentioned this. I've not looked at the TDAC yet but it probably wants to know where you're leaving from as in departure point. Transit isn't really an originating departure point because you've not entered that country.
that's maybe a non-OA. Not a non-O. He can apply for the correct visa online in UK if he lives there. Others have done this. Think someone has given him and you incorrect info.
he can apply for non-O visa ( to come and retire) at Thai embassy on-line in UK. No insurance needed. Then when he arrives in Thailand go to immigration and do extension for 12 months.