If you withdraw $10,000 or more in currency or a cashiers check , federal law requires the bank to report the cash withdrawal to the IRS in an effort to prevent money laundering and tax evasion. I believe if the total of cash withdrawals exceeds $10,000 within a 24hr period it will be reported. In addition to withdrawals, purchases for over $10,000 cash are also reported. This is a good law it makes money laundering in the US difficult.. What government looks for is a steady stream of large cash withdrawals. Unless you are systematically making large cash withdrawals, it is unlikely to raise any red flags.