You have a client Mr and Mrs Joe Smith have bank accounts in Germany. In 2015 when they moved from Germany to USA, they had balance of 150, 000 in a local bank in Berlin. They filed their tax returns from 2015 to 2017 and never reported interest income from bank account in Germany on their personal tax returns. From 2015 to 20175 interest rate was 6%. But they never reported existence of foreign bank accounts to IRS. They both are Scholl teachers and hired a local CPA firm in Houston to file their tax return.