Yes, a bank can ask where you got your money, and in many cases federal law requires it to ask. Banks are also required to file certain reports with the government about your transactions, sometimes without telling you. None of this means you are under suspicion. It means every bank in the country operates under the same anti-money-laundering rules, and how you respond to routine questions matters more than most customers realize.
Why Your Bank Is Asking in the First Place
The Bank Secrecy Act, in force since 1970, requires financial institutions to keep records and file reports that are “highly useful” in criminal, tax, regulatory, and counterterrorism investigations.1Office of the Law Revision Counsel. 31 USC 5311 – Declaration of Purpose The USA PATRIOT Act, passed in 2001, expanded that framework. It requires every bank to run an anti-money-laundering program with internal controls, a designated compliance officer, employee training, and independent audits.2Financial Crimes Enforcement Network. USA PATRIOT Act It also introduced the Know Your Customer framework, which requires banks to verify who you are and understand the nature and purpose of your accounts.
When a teller asks what a deposit is for, they are reading from a script built on those federal mandates. The question is not personal, and it is not optional for the bank.
The $10,000 Cash Rule
Any cash transaction over $10,000 requires the bank to file a Currency Transaction Report with the Financial Crimes Enforcement Network (FinCEN).3eCFR. 31 CFR 1010.311 – Filing Obligations for Reports of Transactions in Currency The rule covers deposits, withdrawals, currency exchanges, and other transfers of physical cash. Cashier’s checks, wires, and electronic payments have separate rules.
Before completing the transaction, the bank has to verify and record your name, address, Social Security or taxpayer identification number, and specific identifying documents such as a driver’s license or passport. Writing “known customer” on the report is not allowed; the bank must record the actual identifying information each time.4eCFR. 31 CFR Part 1010 Subpart C – Reports Required To Be Made – Section: 1010.312 Identification Required Most banks also ask about the source of the cash as part of their internal anti-money-laundering program. If you are depositing $14,000 from a car sale, expect to explain that and expect to be asked for a bill of sale.
The $10,000 figure has not been adjusted for inflation since 1970. Banks file millions of CTRs a year. It is paperwork, not an accusation.
When Banks Report You Without Telling You
Separate from the CTR, banks are required to file a Suspicious Activity Report (SAR) when a transaction of $5,000 or more looks like it could involve illegal activity, money laundering, or an attempt to evade the reporting rules.5GovInfo. 31 CFR 1020.320 – Reports by Banks of Suspicious Transactions A SAR is a judgment call. A transaction with no apparent business purpose, an explanation that does not match the customer’s normal activity, or funds that appear to come from illegal sources can all trigger one.
Banks can also voluntarily file SARs on transactions below $5,000 if they think the activity is relevant to a possible legal violation. There is no truly safe amount below which unusual activity goes unnoticed.
Here is the part most customers do not know: federal law prohibits the bank from telling you a SAR has been filed. Any employee who tips off a customer is breaking the law.6eCFR. 12 CFR 208.62 – Suspicious Activity Reports If the bank asks questions, files the report, and then processes your deposit normally, you will never know the report exists. SARs go straight to FinCEN’s database, where law enforcement can pull them during investigations.
Do Not Split Deposits to Stay Under $10,000
This is the single most costly mistake customers make. Deliberately breaking up cash deposits to stay under the $10,000 CTR threshold is a federal crime called structuring, and it does not matter whether the underlying money is completely legitimate. Splitting it up to dodge the report is itself illegal, punishable by up to five years in prison and fines.7Office of the Law Revision Counsel. 31 USC 5324 – Structuring Transactions to Evade Reporting Requirement
The definition is broad. Depositing $9,900 on Monday and another $9,900 on Wednesday, breaking $15,000 into three deposits of $5,000, or spreading deposits across multiple branches all count as structuring if the purpose is to avoid a CTR. FinCEN’s guidance defines structuring as conducting transactions “in any amount, at one or more financial institutions, on one or more days, in any manner” to evade CTR requirements.8Financial Crimes Enforcement Network. Frequently Asked Questions Regarding Suspicious Activity Reporting Requirements Tellers are trained to spot the patterns, and structuring is one of the primary triggers for a SAR.
Civil penalties can equal the full value of the currency involved in the structured transactions.9Internal Revenue Service. Bank Secrecy Act Penalties If you have $20,000 in legitimate cash from a garage sale, the right move is to deposit it all at once and let the bank file the CTR. A CTR is paperwork. A structuring charge is a felony.
What to Bring So the Conversation Is Short
The documents a bank wants depend on where the money came from. Walking in prepared avoids holds and follow-up questions.
- For a vehicle, boat, or property sale: a signed bill of sale showing price, date, and buyer’s contact information. A copy of the title transfer strengthens the paper trail.
- For a cash gift: a written statement from the giver confirming the money is a gift with no expectation of repayment.10Internal Revenue Service. Form 8300 and Reporting Cash Payments of Over $10,000
- For an inheritance: a distribution letter from the estate’s executor or attorney, or a copy of the probate court order.
- For wages: recent pay stubs or an employment verification letter.
- For business revenue: invoices, sales receipts, or financial statements that match the deposit amount.
- For gambling winnings: the Form W-2G the casino issues for winnings above the reporting thresholds.11Internal Revenue Service. Instructions for Forms W-2G and 5754
- For cash brought in from abroad: a stamped copy of FinCEN Form 105, which anyone bringing more than $10,000 in currency into the United States is required to file with Customs at the time of entry.12Financial Crimes Enforcement Network. FinCEN Form 105 Report of International Transportation of Currency or Monetary Instruments
What Happens If You Refuse or Lie
Declining to explain does not end the conversation. It escalates it. The bank can place a hold on the deposit under Regulation CC and separate contractual authority when a transaction raises compliance concerns.13eCFR. 12 CFR Part 229 – Availability of Funds and Collection of Checks (Regulation CC) If compliance cannot resolve the questions, the bank can freeze the account, blocking all activity, or close it outright and mail you a cashier’s check for the balance.
Involuntary closures tied to suspected fraud or compliance failures are typically reported to specialty consumer reporting agencies like ChexSystems and Early Warning Services.14Consumer Financial Protection Bureau. Will It Hurt My Credit if My Bank or Credit Union Closed My Checking Account? Those records stay for up to five years and make opening a checking account elsewhere difficult during that time. The bank will also probably file a SAR, without telling you, and you will have no opportunity to contest it.
Lying is dramatically worse than refusing to answer. Knowingly making a false statement to influence the actions of a federally insured financial institution is punishable by up to 30 years in prison and fines of up to $1,000,000.15Office of the Law Revision Counsel. 18 USC 1014 – Loan and Credit Applications Generally; Renewals and Discounts; Crop Insurance That covers fabricated explanations for the source of a deposit. On the civil side, willful Bank Secrecy Act violations carry fines that are periodically adjusted for inflation, and certain violations involving special compliance measures can trigger penalties of at least twice the transaction amount, up to $1,000,000.9Internal Revenue Service. Bank Secrecy Act Penalties
If you can explain where the money came from, just explain it.
Pushing Back on a Freeze or Closure
If your bank freezes or closes your account and you believe the action was unjustified, start with the bank’s compliance department and ask for the specific reason in writing. Sometimes an account is restricted over a misunderstanding that documentation resolves. Bringing in the bill of sale or gift letter you did not have on deposit day may be enough.
If the bank will not cooperate, file a complaint with the Consumer Financial Protection Bureau. The CFPB forwards complaints to the bank, which generally must respond within 15 days, or up to 60 days in more complex cases.16Consumer Financial Protection Bureau. Submit a Complaint A CFPB complaint can pressure the bank to release frozen funds, reopen an account, or correct inaccurate reporting to ChexSystems. If you have been reported to ChexSystems, federal law also gives you the right to request a free copy of your report and dispute any inaccurate information directly with the agency.
One boundary worth knowing: a complaint will not undo a SAR. Those filings are permanent and confidential, and the customer has no route to review or contest them.