What are the rules for applying for a Non-O retirement visa extension in Thailand?

The minimum number of days to apply for a Non-O retirement extension is typically 30 days before expiration, with some locations like Bangkok, Chiang Mai, and Phuket allowing applications 45 days prior. When increasing your bank balance from 400,000 to 800,000 THB, you should ensure this increment occurs at least two months before the extension application date, rather than the expiration date. It's advisable to confirm specifics with your local immigration office, as requirements can vary.