Is there an official amount of time that a home country background check remains valid for applying for a job/work permit in Thailand? Thank you.
Probably yes, but ...
Immigration usually doesn't care as long as one is in your application package.
Employers aren't as fussed about it 6 months + 1day is still 6 months.... unlike Korea where they are anal about it.
We used a background check that had already been done for us for our job in the States -- it was around a year old, I think.
But actually, I'm not even sure if anyone even looked at the background check. They never asked for it, although my husband submitted it with the other paperwork. But he's working for a uni - maybe they're stricter if you're working with little kids.