They are aware of only those bank accounts that earned interest in previous tax years. Banks are legally obligated to report any interest paid to their account holders. Your bank will send you a copy of the 1099 Interest Income report at the beginning of the year. Therefore, if your bank account does not earn interest, the IRS probably does not know about it. If you have submitted a financial statement to the IRS when entering into an Installment Agreement, all bank accounts listed will be known and subject to a bank levy.