My old passport is already full, so I applied for a new one at my embassy, and it's now ready for pickup. Obviously, the embassy will somehow invalidate the old passport by cutting or marking it, except for the pages with my existing long-term visas, (like the 10-year American visa). However, I have a question about leaving Thailand.
Currently, I'm on a 30-day extension of the initial 30-day exemption stamp, which technically isn't even a visa but rather a "permission to stay" under Thai law, if I'm not mistaken. What should I do in this case? I plan to do a "visa run" next month, traveling to another country for a few days and then returning. But before that, should I transfer those stamps somehow? Or should I just present the old passport with the page containing my current stamp (assuming it's not destroyed) and return using the new passport?