I'm traveling back to Bangkok with a new passport and my old one with non b extension stamp. I'll need to go and transfer the stamp to the new passport at Chaengwattana. Is the embassy letter required? (No.2) Thank you

No.

What is pp country. 

20 hours ago, Plissken said:

I'm traveling back to Bangkok with a new passport and my old one with non b extension stamp. I'll need to go and transfer the stamp to the new passport at Chaengwattana. Is the embassy letter required? (No.2) Thank you

I am US, and didnt not need a lettet from the embassy, only downloaded the immigration form for transerring of visa information from old to new passport.

On 3/13/2025 at 6:48 PM, Plissken said:

I'm traveling back to Bangkok with a new passport and my old one with non b extension stamp. I'll need to go and transfer the stamp to the new passport at Chaengwattana. Is the embassy letter required?

Most western embassies do not issue the letters anymore. When I transferred the stamp to my new passport the Imm officer had a list of countries that no more issue these letters and I didn't need one. Call your embassy and check.