Go back Thai with both old and new passport. When u enter, show the new passport with old one. The officer will stamp and mark as a new passport. Then go to immigration where u get ed visa. Go change visa there. They will change for u free.
Last time, I got stuck at departure immigration as my finger print is not match when I come in. But after 15min they chit chat with his senior and take fingerprints let me go. Next time I come back no problem.
u can apply at Hanoi. I did apply last month everything smooth apply on Monday and they said pick up Friday. Actually can pick up Wednesday or Thursday
actually I think it is not important where do u buy TR visa. Only hope to have a officer with good mood when u enter Thailand again. In case prepare some cash for bribe.
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