Is possibile for a 12 years old thai citizen board on plane for a domestic flight,without any documents?

Sent from my SM-N9006 using Thaivisa Connect Thailand mobile app

If security is doing their job, no. He should simply use his ID card.

no

without any documents

Minimally (hopefully) one would need a boarding pass, unless the seat assignment involved a wheel-well.

For domestic, intra-Thailand flights, I often check in on-line, print a boarding pass at home, do not check luggage and clear security where they only look at the boarding pass.

If you check in at the airport counter I am pretty sure they will ask for a photo ID; not sure about using an automated kiosk?

However, I haven't done this in a few months and given various recent security concerns there may be a requirement for a photo ID.

Edited April 30, 201412 yr by lomatopo

I have taken quite a few flights recently and, at least with Thai Airways and Bangkok Airways, photo ID was required each time; this did include a hop where I checked in at the check-in kiosk.