What documentation do I need to apply for a 90-day Non-O visa in Thailand based on retirement?

Sorry, but for the application of the Non Immigrant O visa the money does not have to be seasoned in the bank. You will get this visa with 90 days of stay and after 60 days you can apply for the 1 year Extension of Stay and than the same documents are needed but the money need to be seasoned in the bank as mentioned.

It can differ with needed documents at other Immigration Offices but this list is almost covering all you need, so be prepared that your local Immigration office want some a other documents: Application Form (you get at Immigration Office)

1 Passport picture

Copy Id page passport

Copies of visa in passport

Copy Admitted to Stay stamp

Copy TM 6 Departure card

Hand drawn map of area of the house

When using bank:

Bank letter (max 7 days old) + letter income is coming from abroad

Copy Bank book first page

Copy Bank book last pages with 2 months history for first application or 3 months consecutive application. Minimum balance 800.000 Thb

Be aware that the Bank account is in your name only, with joint account the balance is divided over all account holders.

When using income:

Affadavit from Embassy, minimum 65.000 Thb income a month

When using combination

Bank letter (max 7 days old)

Copy Bank book first page

Copy Bank book last pages with 2 months history for first application or 3 months consecutive application.

Affadavit from Embassy of monthly income

Combination bank + income must be minimum 800.000 Thb.

Copy Lease Agreement

Singed copy ID landlord front+back

Signed copy House book landlord

Fee 1.900 Thb