I have DTV and toing away from Thailand and coming back with a new passport. Will I be able to enter with a new passport and get the 180 days or do I have to enter with VOA, go to immigration and transfer my DTV to a new passport?
TLDR : Answer Summary
You can enter Thailand while holding both your new passport and your old passport that contains your DTV. It's important to carry both passports as the DTV cannot be transferred to the new passport. If you have an e-visa, you should also bring a photocopy of the old passport along with the e-visa documents.
DTV VISA RESOURCES / SERVICES