Banks are required to report when customers deposit more than $10,000 in cash at once. A Currency Transaction Report must be filled out and sent to the IRS and FinCEN. The Bank Secrecy Act of 1970 dictates that banks keep records of deposits over $10,000 to help prevent financial crime.

In 2026, the amount of cash you can deposit into a bank account depends more on reporting thresholds and fee structures than a hard legal limit on the total sum. Generally, there is no maximum limit on how much of your own legal tender you can put into a bank. However, in the United States, any cash deposit exceeding $10,000 triggers a Currency Transaction Report (CTR) sent to FinCEN under the Bank Secrecy Act. In India, depositing more than ₹50,000 in a single day typically requires quoting your PAN, and total annual cash deposits exceeding ₹10 Lakhs are reported to the Income Tax Department. Most banks also impose "cash handling fees" once you exceed a certain free limit (often 3–4 transactions or a set dollar amount per month). While you can technically deposit millions, you must be prepared to provide documentation for the "Source of Funds" to comply with Anti-Money Laundering (AML) regulations, as banks are legally obligated to flag "suspicious" patterns like "structuring," where large sums are broken into smaller deposits to avoid reporting.