There are federally mandated targets in the US for notifying the IRS, but it's bigger than that. As an employee of a large Bank of American origin, I can tell you that they use a program called "Know The Customer (KTC)" which mandates that account reps, tellers, etc know pay close attention to what your usual business is for deposits and withdrawals. If you suddenly deposit or withdraw an unusually large or different amount, they will flag you for review, regardless of whether it meets the $9,999 flag for IRS notification. So, in essence - if you do something dramatically out of your normal routine they will report you and start watching you closely.