I currently have a tourist Visa, that needs a 30 day extension. Visa is is old Passport. Due to number of pages remaining, I new passport was gotten. Can the visa extension happen, without the Visa being transferred to the New Passport? The extension would have to be done at the Phuket Immigration. (If that matters)
TLDR : Answer Summary
If you have a tourist visa in an old passport and have obtained a new passport, you can still extend your visa. Immigration offices do not transfer visa stickers to new passports, but you can take both your old and new passports along with a letter from your consulate stating that you replaced your passport. When you visit the Phuket Immigration office, they will note your passport switch, move your entry stamp to the new passport, and process your 30-day extension in your new passport.