If you had a financial interest in or signature authority over foreign accounts exceeding $10,000, you need to file a Foreign Bank Account Report (FBAR). An unfiled FBAR can lead to a $10,000 penalty for non-willful violations and much higher penalties for willful violations.Aggregate Account BalanceThe $10,000 threshold is based on your aggregate account balance. That means if you own two foreign accounts and their combined balance exceeds $10,000, you need to file an FBAR even if neither account exceeds $10,000 on its own.The FBAR filing requirement is also based on the highest account balance during the year. If your account balance exceeds $10,000 for even one day during the year, you need to file an FBAR.FATCA Filing RequirementsThe Foreign Account Tax Compliance Act (FATCA) imposes different requirements on taxpayers with foreign accounts. This may require to file a Form 8938, Statement of Specified Foreign Financial Assets.The Form 8938 filing requirements for taxpayers living in the U.S. are as follows: