Can we convert a visa exempt entry to a Non-O retirement visa in Thailand, and do both spouses need to have 800k THB deposit?

It might not be possible to transfer from visa exempt. They can from applied tourist visa.

Both need 800k.

What passports will you be entering Thailand with because it's possible your Emn=bassy still does the income affidavit which negates the need for a Thai bank account for an in country Non-O application?

You can definitely get a conversion from a touristic entry, for a fee of 2000 THB, to an initial 90-days Non-Imm-O Retirement Visa on Immigration inside Thailand without the need of 800,000 THB sitting in an already existing Thai bank account.

It is possible if (!) your embassy in Bangkok is still issuing an income affidavit, confirming you make more than monthly 65,000 THB of income.

Using the income affidavit renders superfluous the need having to get a bank account opened, which is not possible on a touristic entry.

You would need a rental contract of a minimum of three months on most Immigration offices.

Then armed with the initial 90-days visa, you could get a Thai bank account opened.

You can apply for the one-year extension of stay before the 90-days out of the initial Non-Imm-O visa expire. You would again need another income affidavit from your embassy. The fee of this application is 1900 THB.

*** However, if your embassy isn't issuing an income affidavit anymore, then only two options are doable:

EITHER

use an agent and buy the "full package" (costs up from 45,000 THB to 80,000 THB) the "full package" meaning the opening of a bank account, initial 90-days Non-O visa and subsequent 12-months extension.

OR

apply for the Non-Imm-O Retirement Visa outside of Thailand, enter, open the bank account ( you can do it all by yourself) transfer your own funds of a minimum of 800,000 THB, and as soon as the deposit has matured in your account for two months, apply for the 1-year extension of the stay permit based on retirement, for a fee of 1900 Baht.

You have not told us your passport country, so we do not know if your embassy in Bangkok is still issuing income affidavits, or not. As this is IMPORTANT if you want a positive and correct reply.

Get the non o before you come here and yes you each need 800,000 in the bank in separate accounts, if you can’t do that get a tourist visa, visit and go home

Why not applying for the 90 day non-o and following the usual process?

I think you will need an agent to do it that way. Better to be in your home country where you can use the funds in your own account to qualify.

Unless you already have thai bank accounts you won't be able to do that. You should each apply for a 90 day Non-O visa based on being over 50 prior to travelling to Thailand else you will have to leave again to do so

Spoke with a visa agency yesterday was quoted 55k