yes, there are reissue penalties, refund charges, etc. on any airline ticket...if one bought a "cheap" ticket, then those type of tickets can't change dates at all....
but, it sounds like the OP wants to stay in Thailand (without having to do a Border Bounce) longer than 90 days, and, also seems that they may not have a Thai bank account yet, so, the easiest solution would be to obtain a Thai E–Visa, then try to re-book the airline ticket (with those change fees/penalties) or get a new airline ticket
if travel plans are flexible and there are no emergency/urgent circumstances, then why not change flight departure to obtain a Thai E–Visa beforehand, then, with a Thai E–Visa in hand, make entry into Thailand
Thank you very much for your detailed report about your experience obtaining a DTV E–Visa from the Thai Embassy in Vientiane, Laos under the Category of Thai Soft Power with Thai Cooking Classes
in fact, the TDAC QR Code is envisioned and in the future will most likely be required for more transactions, not just with Thai Immigration, but other Thai government entities, as stated in the draft regulations by Thai Ministers
in the original Thai language Ministerial Regulations implementing TDAC, several times TDAC is referred to as "TM.6 Online", thus any old Thai Immigration requirements needing the old Paper TM.6 Card will most likely ask for the TDAC QR Code (printed out hard copy) now and in the future
The monthly pension of at least 2.000 € Euros is only specific to the Thai Embassy in Paris for them to issue a Single Entry Non–O (based on over age 50 years old "retirement") Thai E–Visa
Now, using that Thai E–Visa Non–O from the Thai Embassy in Paris to make entry into Thailand, your local Thai Immigration Office in-country (in Thailand) will have different requirements for an Extension and you would be required to start again with ฿ 800.000 Baht, as you wish to use the ฿ 65.000 Baht/month method can only be done on a subsequent (year 2) Extension =
if you let your "year 1" Extension of Stay expire and then afterwards, go obtain a new Non–O E–Visa at the Thai Embassy in Paris, then that resets everything regarding Extensions of Stay obtained (only available in-country, in Thailand) and starting all over with 800k for Year 1, then could be able for the Year 2 Extension of 65k/month....
initially Posted on 14 Nov 2022 and Updated on 2 Jan 2024:
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IMPORTANT:
Thai Visa is for entering Thailand. It is therefore issued to those who are outside of Thailand and will visit Thailand. Therefore, your visa application will be rejected if you are already in Thailand during the visa process.
Royal Thai Embassy, Bucharest has the authority to provide visa service only to those who are in Romania and Bulgaria for the entire visa process. Therefore, your visa application will be rejected if you are outside of Romania or Bulgaria.