What are the requirements for converting a tourist visa to a NON O retirement visa in Thailand?

remember that Chiang Mai requires you to have 21 days or more left on your current stamp to start the conversion process to a Non-O visa.

Just to explain: It is possible to convert a Visa Exempt Entry or Tourist visa into a Non Immigrant O visa based on being over 50 years of age at some Immigration Offices inside Thailand. If you use the banked money option of minimum 800.000 Thb, you must have proof that this money comes in from abroad and there is no seasoning. This means as soon as the money is in the account your can apply for the conversion. The visa you get is valid for 90 days. If you like to stay longer than these 90 days you can apply after 60 days for the 1 year Extension of Stay based on being over 50 years of age. For this Extension of Stay the money needs to be 2 months prior application date in the bank and stay there for 3 months after application date and rest of the year not lower than 400.000 Thb. To stay long term in Thailand and arrived with visa exempt or tourist visa, you go trough 2 different applications with different requirements.

Non0 based on being over 50, copies of all the pages in his passport,

Letter from the bank confirming the money came from overseas.

Also an updated copy of his bank book updated on the day he applies,

2 passport photos,

Copy of landlords id and blue book.

The visa application filled in,.

Which Immigration office is he going too?

In Bangkok it is 15 days left on his stay, Chang Mai 21 days and other offices can have different days or are not allowed to convert a Tourist visa into a Non Immigrant O visa. There is no seasoning of money required for a conversion, the money must come from abroad. Best is to visit your local Immigration Office, ask if conversion is possible there and the hand out with requirements.