What is the best way to demonstrate ongoing bank account balance for a retirement OA extension in Thailand?

To demonstrate an ongoing bank account balance for a retirement OA extension in Thailand, it is generally required to provide an official bank statement stamped by the bank, rather than just PDF printouts from an app. You will typically need to present your bank book, a recent official bank letter, and a balance statement for the past year. Different locations may have varying requirements, so it is advisable to confirm with your local immigration office for their specific documentation policies.