Originally Posted by
BinSabai
actually the regulation of the Thai authorities is clear. But check in staff in other countries sometimes enforce them and sometimes not...
Agreed, which is the part that I replied to - Check in / Gate Agents. Not anything about Thai Authorities.
I have only been asked about Onward Travel once when checking in for a flight to Thailand. I was arriving on a "one way" and departing on a separate "one-way". The other 60+ times, nothing asked at check-in, even with similar one-way arrivals.
I have never been asked about it by Thai Authorities upon arrival.