You might want to get the 90 day Non-O visa from the thai consulate in your country before you wing your way here although you will be fine applying for the in country 90 day Non-O with a passport that expires in July 2027.
Your passport will not expire within the time you will get on the Non-O visa OR the year extension (figuring from Aug, that's 90 days so about November 2025, and then a year extension is Nov the following year (2026)
Your passport expires 8 months AFTER that year extension (so you'd renew the passport before you went to get the second year extension Nov of 2026)
Machine Readable Zone, it's that set of numbers letters on the bottom of the data page of your passport, you scan that and the system auto fills in the data (but it gets it wrong a LOT of the time and if you submit an application with a data entry error it's cancelled and you lose your funds)
You need to keep the 800K baht in the bank account for 3 months after your yearly extension is granted and after that the balance can't go below 400K for the rest of the year (before you get it back to 800K 2 months before your next yearly extension
You should GO to your immigration office and get the hand out listing the requirements for the yearly extension based on retirement at that specific office well before you're going to go for the extension, that way you know what copies, documents, bank letter, statement, updated bank book, map, photo, etc you need to get together
As a rule extensions are added to the expiration date of your current stamp
The only time an extension isn't added to your current expiration date is if you are getting an extension for a different reason than you have the current visa/extension
In Bangkok you can go 45 days before your current stamp expires to apply for an extension
What stamp are you on now and what extension are you trying to get ?
Anonymous participant right, and that's because Koh Phangan, Koh Samui and Jomtien all tell people who enter on 60 day free stamp OR real 60 day tourist visas to come when they have a week or less left on your stamp
BUT
You aren't here free stamp or on a tourist visa 😮 you have a Destination Thailand Visa and you could have applied for a new extension any time you had 30 days or less left on your entry stamp 🙁
The best way to do it would be to move the stamps to the new passport then file the 90 day report under the new passport number so that the new passport number will be in the 90 day reporting system meaning you can do the following 90 day reports online.
Anonymous participant seeing as an extension is for 180 days (it can't be issued any shorter) they aren't gonna care in the least when you're leaving the country
It's all down to the documentation (which is pretty much a carbon copy of the stuff you used to get the DTV at the consulate AND the proof you have 500K baht in a bank account in your name for a month
Anonymous participant 237 many MANY people kept their ED extensions and went to a thai consulate in another country to get a DTV, without any problem what so ever