Your accountant would need to know from your the bank name and address were you had at any given time $10,000 or more in a foreign account. It is a formality to fill out the form. You can do it yourself easy. I use to let my CPA do it when filing my taxes but he charged an extra $100 to complete the form and file. Search online for the form FBAR.
you are a absolutely . correct. Many Falangs here are not aware of this. If you use the 800,000 baht route for retirement That is over the 10,000. You must file FBAR. Just reporting. There is no interest earned