Does the initial Non-O retirement visa require a minimum stay in Thailand to extend to a one-year stay permit?

The initial Non-O retirement visa does not have a specific minimum stay requirement for applying for a one-year extension. To get this extension, you can submit your application with either 30 or 45 days remaining on your current stay permit, depending on the Immigration Office. It's important to note that the Non-O visa itself becomes invalid upon entry into Thailand, at which point you are issued a 90-day stay permit that can be extended.