Do you need to obtain a 90-day Non-O visa before applying for a one-year retirement visa in Thailand?

Yes, that is correct

Your friend needs to go to the local immigration office to get the latest handout of their specific requirements. Here is general information for the first in-country Non-O visa for 90 days based on being over 50, but details vary for each office.

/9.FOR-RETIREMENT-PURPOSES-50-YEARS-OLD-NON-O.pdf

Yes.

YES the Thai Immigration Officer was correct

But it can usually be done at his Thai Immigration office .. Just ask for their list of requirements for the Non O Visa as retiree and the One year extension of stay as retired.

Fulfill the requirements and your friend will have TWO new STAMPS in his passport...

Non O Visa.. 3 months

Extension of Stay.. 12 months

totally correct and it's the mix up in terminology that is throwing you and your friend off the rails as far as understanding the process.

First he's not here on ANY visa on arrival, he showed up here without buying a visa from a thai consulate and got in on a free entry stamp (called a visa exempt entry) for 45 days.

You must first apply for a 90 day non-O visa based on retirement and that requires a minimum of 15 to 21 days left on your current visa exempt entry stamp depending on the immigration office. That cost 2000baht and goes under review between 14 and 20 days then he goes back and gets the Non-O visa and a new 90 day stamp inked in

After that he waits until he has 30 days or less left on that new 90 day stamp AND his 800K baht has been in a thai bank account in his name only for 2 months. Then he applies for the year extension based on retirement for 1900baht. it will be issued on the spot.

Once he has the year extension inked in IF he wants to leave/return to thailand he needs to get a re-entry permit