How do I transfer my DTV to a new passport in Thailand?

Best practice is to transfer the DTV to your new passport at Immigration once you get it.

In theory, you can travel carrying both passports and show the old one with the visa, but in reality it often causes confusion with airlines and immigration officers. Transferring it officially avoids problems on entry, extensions, or re-entry later.

Most people who’ve done it say the transfer is straightforward—just time and paperwork.