Hi all,

I have a Non Immigration O visa, multi entry. I need to leave Thailand shortly and re enter as required by the terms of my visa. Do I need to submit a TM 8 form prior to my departure or any other documentation or just cross the border and then return. Thanks.

Just leave and return.

Nope.

Just leave and return after crossing the border.

If leaving within the prescribed maximum single stay per the visa, nothing required apart from the completed Departure card that you would have received on arrival. When you re-enter, you will get a new Arrival/Departure card and the only thing is to check that the date stamps you get on re-entry are correct (matches the visa stipulations) before you leave the point of entry. Wrong date stamps are infrequent but not unknown. However, they can be a chore to get corrected after the fact.