Maybe both of you,

@St***

and

@Ke***

, should mention the date that your Non-Imm O-A visa was issued. ?

Last time I did a border run was at Chong Chom border crossing. I had the company of a 'local guide'. He 'advised' me to pay an extra 500 bath to avoid the obligation of staying in Cambodia for a least one night. Scam or not, I don't start a discussion for a mere 15 euro. So I paid and returned to Thailand with all the stamps I needed in about 10 minutes ...

Do you still need this letter if you have an updated bankbook ?

What is HCMC ?

The text I show I just the text Immigration. I'm not claiming to know how they will apply it. I'm on a Non-Imm O-A visa myself and I have chosen to change to a Non-Imm O the next time I go to my native country. Otherwise I would have bought health insurance. It is only checked when you ask for extention or if you leave the country. As you can read in other groups when you enter the country some Non-Imm O-A visa holders without have been asked to buy a health insurance within 30 days of their arrival. As always, if they don't check you or even if you don't get cought there is no problem (even for murder, 55) . Im just posting what I know, I don't want to pretend I know better than anyone else.

Pretty clear to me...

It states : "get insurance coverage anyway because failure to do so I think would probably cause a high likelihood of possibly having problems with Immigration at the time of entry to the Kingdom of Thailand"

But even they don't know for sure ..