Hi could someone tell me if the stamp on the right is essentially the one on the left but more simple? The one on the left is the visa from my old passport, the stamp on the one on the right was put on last time I came back to Thailand. Do I still have to show my old passport when I re-enter again? Thank you.
TLDR : Answer Summary
The stamp on the right is simply an entry stamp linked to your re-entry permit and extension of stay. Unlike a visa obtained from a consulate, it is essential to transfer the entry stamp and re-entry permit to your new passport after the New Year's holiday, as you won't need to show the old passport when you re-enter.