Depositing $150,000 in cash into a checking account will trigger mandatory reporting to the IRS and Financial Crimes Enforcement Network under the Bank Secrecy Act. This reporting requirement applies to transactions exceeding $10,000 and is designed to detect potential money laundering activities. The notification process is standard procedure and does not indicate wrongdoing by the depositor.

Banks must file currency transaction reports for large cash deposits, creating a paper trail that could be examined during audits. Depositing the money in smaller increments to avoid detection—a practice called structuring—is illegal and can result in serious consequences. Authorities actively monitor for structured transactions during various compliance reviews.

For inherited cash, banks may request documentation such as death certificates or probate documents to verify the legal source of funds. However, if the cash was already legally yours rather than transferred directly from a deceased person's account, such documentation would be less likely required. The reporting requirement exists regardless of inheritance tax status, as only a handful of states levy such taxes while federal estate tax applies to estates exceeding $15 million in 2026.