You're making this whole thing way more difficult than in needs to be. For your father and for you. For a start. you apply for your Visa - regardless where you are phsyically - from your home country's Thai Embassy website. Go online to the Thai Embassy website in your home country - the country of your passport - where you have legal residence, where you have a driving licence or national ID card or some other proof of official address. Apply for a Tourist Visa. For Leisure. Don't complicate issues with Non-Imm O visas and staying with family. The visa costs twice as much and you don't need to prove you have 24,000 Euros! Only about 750 Euros. Follow the instructions. Scan the required documents. Double check them. Upload them. Pay the fee. There is no need to have to have flights from your home country into Thailand, The Thai Department of Foreign Affairs wants to know how and when you are entering and (more importantly) leaving Thailand. Save or scan the boat booking. And the flight home booking. Upload the files. Book a room at a hotel for the first night - the night you arrive - in Thailand. Ensure it's an online, free-to-cancel booking. Scan it or print it to pdf format. Upload the file. Same with everything else. Save or scan. Upload the file. Double check. Pay the fee. (35 Euro) Depending on Embassy, things can take a while. As this is only a single-entry visa, apply about four to six weeks prior to your date of entering Thailand. The Single-Entry Tourist Visa is valid for three months. That means you must enter Thailand within three months of the visa being issued. Print out the E-Visa. *Also a good idea to have the other documents printed out as well and with you in your carry-on luggage. They give you sixty days from date of arrival, and you can apply for an additional 30-day before that 60 days is up while you're in Thailand\ (see below) IMPORTANT FOR ONCE YOU ARE IN THAILAND If you expect to want to extend your initial sixty days - which you said you want to to - when you get to the private house where you're staying, it is essential the person who is on the house registration book takes it (tabien baan) and her ID card with you and your passports and visas within 24 hours of arrival to their house, and fill in the Alien Registrtion Form. It's free and, depending on you Immigration Office, takes almost no time to process. Five minutes. Fifteen days before your 60 days is up, go to the Immigration Office, with the house owner again, and fill in an extension to extend stay in the Kingdom. This will cost you 1,900 baht per extension. And the queue longer. * Yes people can do online Alien Registrations (it's called the TM 30) but. depending on the distance to the local office, and the technical know-how of the phone user, it's often more simple just to drive to the office. And you're done I hope your father enjoys his trip. Here's a link to the Thai Department of Foreign Affairs . https://thaievisa.go.th/ Pour l'ambassade de France à Paris, cliquez ici https://www.thaiembassy.fr/fr/visa-rdv/e-visa/
