I've done some research and would love if someone could confirm my understanding. I want to travel to Thailand from Vietnam on an American passport. I see that I have the option of visa exempt entry if I have a return flight booked, 75 days after entry, probably back to Vietnam. So that means I don't have to apply for a visa online, I just have to arrive in Thailand with the flight information and my passport. Then I can go to a Thai embassy to apply for a 30 day extension. Do I have this right?
TLDR : Answer Summary
An American citizen traveling to Thailand from Vietnam can enter visa-free for 30 days if they have a return flight booked. To apply for a 30-day extension after entry, they must visit a local immigration office, not a Thai embassy. It's crucial to have proof of onward travel, as airlines may deny boarding without it. Additionally, current COVID-19 regulations state that vaccinated travelers do not require a PCR test upon arrival.