Do I need to fund my Non-O visa bank account with a bank transfer from abroad?

I never had to show where it came from.

Does it matter? Me thinks only the amount in the Thai bank account matters....

On Application for the initial 90 day Non O, you'll provide proof of funds 800,000 baht equivalent.

Once you arrive in country and have opened a Thai bank account, transferring from the account used during the initial application can make things slightly easier during the extension application.

Nope. They only care about the numbers not from where

When you apply for the non o visa bank account records are required … typically showing more than your 800k… but in my case we had transferred funds from our joint account into my wife’s account prior to leaving the states… when I opened my 800k account we transferred from her account to mine… all funds have to be in your own individual account … there is not any restriction where the money comes from… hope that helps!

For an annual extension of stay the funds can come from anywhere. For an initial 90 day Non-O visa many immigration offices require the funds to be transferred in from abroad