In a PUKHET publication they say this:
"However, all foreigners who reside in the country on another type of visa, in particular Non-Immigrant O visas granted to foreigners married to a Thai woman and in charge of a Thai family as well that business visas, must obtain a letter from their embassy asking permission to stay in the country "
In my opinion it is false but I wanted to check with you.
TLDR : Answer Summary
A post discusses the requirement for foreigners on Non-Immigrant O visas and business visas in Thailand to obtain a letter from their embassy for permission to stay in the country. The consensus among commenters is that this information may be incorrect, as such letters are typically only provided for those using Visa Exempt Entry or Tourist Visas.
NON-O RETIREMENT VISA RESOURCES / SERVICES
- Go to the Retirement Visa Section for information on requirements, including age restrictions, financial requirements, and necessary documentation.
- For immediate assistance, contact Thai Visa Centre directly via LINE at @ThaiVisaCentre or Email them.
- Explore recent discussions by using the Non-O Retirement Visa tag in the search box at the top of the page.
- Join the Thai Visa Advice Facebook Group to ask your questions, and get advice from others.