Originally Posted by Savage25

Don't forget this if you don't clear immigration in BKK! Since BKK-HKT is a domestic leg, the crowd will not clear immigration and you may just follow them without thinking.

A former absent-minded boss of mine flew TG SIN-HKT-BKK and followed the domestic crowd at BKK without clearing immigration. That caused him a big problem since he never legally entered the country and a few tens of thousands of baht had to be paid under the table to the immigration department to get an entry stamp in his passport.