Under 31 U.S.C. § 5314 (31 C.F.R. § 1010.350), a United States resident or citizen who engages in a transaction with a foreign financial agency, or who has a financial interest in, or signature or other authority over, bank securities or other financial accounts in a foreign country must report certain information about the transaction or the financial interest in the account. This information is reported on Treasury Form TDF 90-22.1, called a "Report on Foreign Bank and Financial Accounts" or FBAR. In addition, a person who is required to file an FBAR must also check the appropriate box on his or her tax return and file IRS Form 4683 with the return.
[updated February 2014] [cited in JM 9-79.200]