A bank must report a cash deposit exceeding $10,000 to the federal government, according to Forbes.com. This regulation is a result of the Bank Secrecy Act, which is intended to prevent money laundering and tax evasion.
The bank must report a one-time deposit of $10,000 or multiple deposits or withdrawals totaling $10,000 made by the same customer or on behalf of the same customer in one day. This includes deposits that were made at any of the bank's branches. The reporting requirements of the Bank Secrecy Act also applies to any withdrawals or deposits that may appear to be suspicious, even if the deposit only totals $5,000. The report must be made and filed within 15 days of the transaction.