What are the requirements for extending an OA non-immigrant multi-entry visa in Thailand after two years?

To extend an OA non-immigrant multi-entry visa for an additional year after two years, you should visit the immigration office when you have 30 days or less left on your current entry stamp. At this office, you'll need to submit the necessary documentation and meet specific financial requirements, which can vary by location. It's advisable to obtain the list of requirements from your local immigration office beforehand and prepare during your first year if needed.