How do I transfer my son's visas from his old passport to the new one in Thailand?

To transfer visas from an old passport to a new one in Thailand, you generally need to visit the immigration office with your son, as they may require his presence. An online appointment may be necessary, typically under categories related to visa extensions or passport services. Bring photocopies of the old passport's photo and visa pages, the new passport's photo page, and a letter from the embassy. Some immigration offices may also ask for a TM30 form.