Do I need to re-submit all my documents including bank statements to renew my Non-O visa in Thailand?

"the money requirement started at showing ฿800,000 for 90 days prior to applying but after 90 days it drops to ฿400,000" <- this is the requirement to keep your CURRENT extension stay valid.

When you want to apply for a new extension next time, you need to meet the requirement for a NEW application which includes "showing ฿800,000 for 90 days prior to applying" for next extension.

I just wonder...these requirements are all communicated numerous times, again and again.. How much denser are we getting? Just a little reading will give provide almost all the answers one needs for the basics. Some unusual cases, sure, the folks are here to assist.

Simple stuff, you can find answers, try it!

What part of "every year is a NEW application" are you not glomming onto? 😮

You get a "retirement extension" a year at a time <- that's the longest they can be issued for.

At the end of that year it runs out and you apply for a brand NEW yearly extension.

As an example; I'm 62 and have been applying for a new yearly extension the last 12 years, each time, submitting the same documentation, bank letter, updated bank book, forms, copies, hand drawn map, every year. It's the exact same documents every year.

The only think you have to be aware of is IF you are using banked money method you need to have had the 800K baht in your account for 3 months AFTER you got your yearly extension last year, then the balance on that account couldn't go below 400 for the rest of the year and then 2 months before you apply for this new extension it has to be back at 800K baht. <- Those are the seasoning terms that are cut in stone (as in there's no wiggle room at all) for banked money method for a retirement extension

Yes

think of it this way, EVERY year extension is a NEW application for another year. You need all the documents you needed last year all over again.

You will have to submit the same documents you did last year for either your visa or your extension of stay (depending on what you mean by a "non-O").