An FBAR, or Foreign Bank Account Report, is a form the US Department of the Treasury requires for individuals with a financial interest in or signature authority over foreign financial accounts. This form must be filed annually if the aggregate value of these accounts exceeds $10,000 at any time during the calendar year. The FBAR reports foreign accounts such as bank accounts, brokerage accounts, mutual funds, or other types of financial accounts held outside the United States.
Find more about FBAR here: FBAR: Requirements, Deadlines, and How to File