Can I use my 800k bank account for daily expenses under the Thailand retirement NON-O visa?

Not wise. Use a separate account.

Don’t go below 800k at least 90 days before renewal

Yes you can keep the money in an active account that you are using for for daily purchases.

Ok I’m going to add to this as I want to be correct when renewing my yearly extension, if I transfer 65,000 each month on top of the 800,000 for extending my 3 month non o, I am able to use the 65,000 (will be more like 100,000) for living expenses, when I renew the yearly extension in 2027 as long as I show I have transferred over 65,000 each month I will not need to have 800,000 in the account? Is this correct thinking?

I have two accounts. One that I transfer money to from my US account and have my visa fund in, the other I keep a few thousand Baht in to pay for things by QR or withdraw cash. I did it years ago when you had to use an ATM card and card skimming was a thing, but now with card less ATM cash out with the banking app I rarely use the actual card.

You only need that amount on the day your visa is approved after that the m9ney is yours to do what you want with as long as you have the money next year for your renewal

Use TrueMoney. You can scan with it and also use it at 7-11. This way your bank statement for immigration isn’t full of transactions

Something to consider… each and every daily transaction will be recorded and this can make a rather long yearly bank statement that needs to be printed and checked by your immigration officer for your yearly extension. Sometimes it’s easier to keep a separate account for the 800k so that there is little chance of going below the required balances throughout the year. Keep another account for daily transactions - Not necessary to do this but I have found it more convenient 🤗

Yes

Yes, I regularly deposit additional funds into that bank account and use for daily expenses… makes it easy to use scan/qr codes to pay

You've answered your own question. As long is does not drop below 800kthb, I cant say if you can manage it, thats down to you.

Yes

Yes of course as long as you're careful not to drop below the minimum required levels

Yes