visa exemption on arrival question

[MuayThaiGuy]

Hey,

I have a couple friends coming to visit at the end of the month.

Right when they arrive, I will need to head over to Cambodia for a visa run.

When they enter Thailand, they will get a 30 day stamp.

If they were to come to Cambodia with me for a few days, would that 30 day entry stamp they got by flying into Thailand be nullified?

And would they only get 15 days crossing back into Thailand from Cambodia?

They need to stay in Thailand for 30 days.. just trying to figure out if a short visit to Siam Reap would interfere with their ability to do that.

Thanks in advance.

[Namplik]

Yes it will be nullified, if they are from a G7 country the will get 30 days at the border, otherwise they will only get 15 days....

[ubonjoe]

If they only get 15 days on entry at the border they could get a 30 day extension at immigration for a fee of 1900 baht.