Failing to file FBARs (now referred to as FinCEN 114 going forward) on your foreign accounts is a costly mistake. A law since 1970, if the sum of your foreign accounts exceeds $10,000 at any point during the year you must also file a FBAR (Report of Foreign Bank and Financial Accounts). Not filing an FBAR has a civil penalty and each willful violation carries a penalty of the greater of $100,000 or 50% of the account balance for each year you failed to file an FBAR. This can also be considered a criminal offense with fines up to $500,000 and up to ten years in prison. The statute of limitations is somewhat of a gray area as FBAR violations are considered a financial crime, not a tax crime.