Do I need to show onward travel when entering Thailand with a 30-day visa exemption?

It's 30 days by air. Or 14 by land ...

visa in arrival is 14 days

I've done it before no outbound flight booked but maybe i was lucky

A visa to Cambodia is faster and cheaper to get. You can get one on arrival for $10 or $20. I forget which one. Vietnam is $100 or more. Also, if you haven’t seen Angkor Wat in Siemreap, I highly recommend it. It’s mind altering if you are interested in history

I suggest going on book a cheap flight with either Airasia or Vietjet to either Cambodia or Vietnam. (HCMC, Danang or Hanoi have international arrival to Vietnam. from Bangkok, Chaing Mai or Phuket

If you are granted a 30 Visa Exempt entry, Immigration as well as the airline may ask for a Onward Ticket and as a good boy scout, you should be ready for it... Just check BestOnwardTickets.com . Got this request in Hong Kong recently and was glad I had it. Passed with flying colors ;o) I know its states valid for 72 hours, but I sent an email request and got a 7 day extension at no additional charge. Safe travels

I have been asked once by the airline flying me, as well as once by Thai immigration. Both pre Covid though. As I wasn't staying over a month anyway, I had them booked already.

You may as well book one of your excursion flights now. Just in case.

Your airline will want to see onward travel within 30 days, technically so do Immigration but they rarely ask to see it.

Vietnam is cheap. Maybe half the price of Thailand. Cambodia is a little more expensive. Loas is pretty dull.

I’m same. I’m doing Thailand then Philippines but I’m reluctant (commitment phobic) to book the onward ticket 🤣

Keep in mind visa exempt gives you 30 days and you can get a 30 day extension so you could spend the first 60 days in Thailand and then MoveOn

I always use Orbitz, book a flight and cancel within 24 hours with full refund guaranteed. That way I always have a ticket at hand. Of course you have to make sure your flight does not take the full 24 hours....

Depends who your flying with some do some don't require an outbound ticket

Does anyone have a link to these cheap bus ticket sites?

I'm assuming you mean Visa Exempt and not Visa on Arrival.

Immigration rarely ever asks about your plans to exit the country.

Where you will likely run into trouble is when you go to board your flight to Thailand. It is the airline's responsibility to ensure that you meet the entry guidelines to the country you are flying to, so they may ask to see proof of onward travel before checking you in or letting you board, and if you cannot show them something, they may refuse to let you board.

If you want to be sure, either make your plans now to visit other countries and book your travel, buy a cheap throwaway bus ticket to a neighboring country, or book an onward travel ticket through one of many websites.