Just thinking out loud. Assuming one held a multiple entry Non immigrant B visa, and you wanted to take a break or a little holiday to another country or even fly back to the States for a while. Would that be OK and normal? Usually people here seem to talk about the multiple reentries from the point of view of short term border visa runs. I am thinking a bit past that.

Is there a time limit on when one must be back after exiting Thailand? Is it a routine trip with no advance paperwork, or do you have to do something in advance to keep the B Visa?. I can imagine something silly like a 30 day visa on arrival getting entered into the system and superceding the B visa when you reenter?

Thanks.

No limit other than the enter before date on the visa. And never any paperwork needed.

As long as you put a visa number on your arrival card the chances of getting a 30 day stamp are small. But if it did happen you could go to immigration and get it changed. It is always best to check the date they stamp in your passport before leaving the arrival immigration area.

Your Visa will have a "Use by" date on it. As long as you return before that date you will have no problem.

You people are great. Thanks for the replies.