Will be arriving in Bangkok early in January -- have rentals there and in Hua Hin lined up until mid-March - will be arriving under the 30-day US no visa needed and immediately applying for appropriate O visa and Retirement extension as we plan long-term stay.  I see on some US embassy websites that Thailand requires exit ticket but have also heard that it is NOT immigration on the Thai side who cares but that those people who have been hassled about not having an exit ticket it is the AIRLINE who is requiring it?   So if our airline (China Eastern) does not require it, would we safe (no unnecessary airport delays) not having an exit ticket as we can state our intentions and have proof of our pre-paid rentals? Appreciate any knowledge/experiences on this ( I know we could also show a bus ticket out (cheaper) if needed but really have no idea where to get that online -- even though we still wouldn't be using it) THX!

If you are staying more than 30 days you need a Visa.

Without one you could be refused entry to the flight without an onward flight ticket within 30 days.

Get a single entry tourist visa for your trip, if you can. It eliminates a possible stressful experience at the airport.

 

(For short haul flights, it is quite likely no check will be made.) If you have neither a visa, nor an onward flight out of Thailand within 30 days, the airline check in staff will probably initially refuse to check you in, referring you to a supervisor. I have on a number of occasions traveled to Thailand, intending to enter visa exempt and without an onward flight ticket. I have always managed to convince the airline supervisor  that Thai immigration will have no problem, and to check me in. Sometimes, I have needed to sign an indemnity form promising to reimburse the airline for any financial costs they incur should I be refused entry to Thailand. Airlines have become stricter since Thailand started denying some entry on visa exempt entries in mid 2015.

If your airline doesn't require it you will not be hassled.

If trying to do this without a Tourist Visa or outgoing-ticket - be sure to arrive a bit early for check-in, so you have time to make an online-booking, if necessary.  You only need a flight "out of Thailand" within 30-days - so can be a cheap flight from anywhere in Thailand to Kuala Lumpur, or similar.

 

If planning to do a Conversion to a Non-O in Thailand (1st step, before applying for you 1-year extension-of-stay), entering with a Tourist Visa would allow you more time (60-days initial stay vs 30-days) to deal with any paperwork-delays in that process.