Enforced by US Department of the Treasury (Internal Revenue Service)
http://www.irs.gov/businesses/small/article/0,,id=148849,00.html
FBAR is a form that must be filed with the Internal Revenue service by anyone with a financial interest in or signature authority or other authority over any financial account in a foreign country, if the aggregate value of these accounts exceeds $10,000 at any time during a calendar year.
Key Facts
The FBAR is required because foreign financial institutions may not be subject to the same reporting requirements as domestic financial institutions. The FBAR is a tool to help the United States government identify persons who may be using foreign financial accounts to circumvent United States law. Investigators use FBARs to help identify or trace funds used for illicit purposes or to identify unreported income maintained or generated abroad.
Additional Information
FAQs Regarding Report of Foreign Bank and Financial Accounts (FBAR) - Filing Requirements
Who it affects
US citizens and businesses with foreign financial accounts.