After some clarification please
My friend holds a Myanmar passport and will enter Thailand on 12/7 as a tourist he will enter via phuket airport
I believe he can stay 14 days without visa does he have to exit on the 25th or is 26th ok
Thank you in advance
TLDR : Answer Summary
A Myanmar passport holder can indeed enter Thailand as a tourist without a visa and stay for a maximum of 14 days. If your friend arrives on 12th July, he must exit by the end of the day on 25th July, making the 26th July an oversstay.