I have just spoke to a thaiwomen who is in a bit of distress about her son.

Here is her scenerio

She has a half thai/american son born in thailand,

Went to US when 3 months old with her and hubby,

She is divorced now and returned to thailand with son, no contact with hubby anymore.

kid entered thailand on US passport, has 1 year visa has to report every 90 days.

She now has a thai passport for him but thai immigration says he still has to report every 90 days.

She is worried about this.

I told her to leave thailand at closest border which is laos with him and re enter thailand on thai pasport, problem solved.

Is this the case? or doesnt he have to leave at all?

Air departure/arrival is normally required for passport switch as a ground crossing you must show departure stamp from other country. Have her take a cheap flight to KL or Singapore and on return use Thai passport for entry.

If she is close to land border she could ask if they would allow her to do - they might as it is obviously not something wrong so nothing lost is asking.