if you would be so kind, then could you upload a scan or photo of this ink stamp you received from your local Thai Immigration Office inside Thailand, redacting any personal identity information
Also, do you mean you had a DTV Visa STICKER from the Thai Embassy/Thai Consulate physically in your old passport, or, do you have a DTV E–Visa PDF File that you printed out as a Hard Copy Paper???
1.) You would get a New Passport reflecting your New legal Name
2.) you are gonna have to ask the Thai Embassy/Consulate that issued your DTV Visa Sticker/DTV E–Visa to see if they are able to Amend/Modify your existing DTV Visa Sticker/DTV E–Visa to reflect the New Passport (with new name) or not
3.) if the Thai Embassy/Thai Consulate is not able to, then you have to apply for a New DTV E–Visa with your New Passport
4.) otherwise, just continue to use your Current Passport (with your old legal name) until your current DTV Visa Sticker/DTV E–Visa expires
5.) Happy to hear of other alternatives and experiences that a Thai Immigration Officer at Arrival Entry Port would accept in such a particular circumstance....
in my personal opinion, nowadays, consider the Thai government's Board of Investment (BOI) LTR Visa (Long–Term Resident Visa) as the better and cheaper Thai Visa to consider vs. Thailand Privilege Visa
* All applicants must be residing within the UK/Ireland/UK territories when apply for the Visa. The Royal Thai Embassy has the right to cancel the visa applications should you fail to provide the evidence of your presence within the UK/Ireland/UK territories while applying for the visa.
Payment in Cash Thai Baht, but, the Thai Immigration Officers on Departure at Suvarnabhumi Airport are installing Bank Card EDC Terminals to accept Bank Cards, but dunno if currently in use or not