Non-Immigrant O Visa

[lanky]

I have a non immigrant O visa have another 3 exits to use the first one we flew to singapore the next one I want to use will be cross a border crossing into masea. Burma is that sufficient for the visa to be valid

[Mario2008]

You can use any international border (land or air), so yes.

[bobl]

Yes, a land crossing to Mae Sai is sufficient to activate your next 90 days. Do take care to point out you're doing so, or you might end up with a 15 day exempt stamp. They're pretty sharp up there but you can't be too careful. Better to make sure you got your 90 days there and then, than have to visit the "wrong stamp" department in immigration.

[Lite Beer]

Actually you have Multiple entries, not another 3.

[lopburi3]

That means unlimited number of entries up to 90 days during the one year validity. This can be helpful if you are near a border or want to go shopping you just leave and return for a new 90 day period of stay. You do not need to worry about only having three such entries with a multi entry non immigrant visa.