One poster commented the FBAR report had to be filed by end of June. As of the 2019 report the filing date coincides with the IRS income tax due date of 15 April. The date due for the FBAR is not extended beyond that date as with your tax return. Also, as said the report can be done in five (maybe ten) minutes on line and has nothing to do with any taxation. It is related to financial crimes activities only. The amount required to be reported is the peak value of the account(s) during the year in USD. Add these amounts for multiple accounts and use the official exchange rate from https://www.fiscal.treasury.gov/reports-statements/treasury-reporting-rates-exchange/current.html to convert Thai baht to USD. There is no connection or impact on your income tax liability but as has been said there can be extremely heavy fines for failing to report. Make sure you go to the official government site at site https://bsaefiling.fincen.treas.gov/main.html to file this report on line. There are many offers available at a high cost to do this report for you but you can easily do the report yourself.