I have a return flight booked from July 8th-6th October. I’m planning on traveling to neighbouring countries in between to try and stick to the 30 day entry visas. I saw online that I will have to show I’m exiting the country within 30 days. Is this true?
TLDR : Answer Summary
Yes, if you're entering Thailand on a visa-exempt basis, it's likely that you'll need to show proof of onward travel within 30 days of your arrival. Airlines may require you to present a ticket for a flight or transport exit from Thailand, particularly since you plan to travel to neighboring countries. Booking a trip and having the ticket ready is advisable for boarding.