Currency Transaction Reports and Structuring: US Rules Explained

Few US anti-money laundering rules are as well known, or as often misunderstood, as the $10,000 cash reporting threshold. Banks and other financial institutions file currency transaction reports, and a separate prohibition makes it unlawful to break up transactions to avoid those reports. This guide summarises the relevant sections of 31 CFR Chapter X as shown on the eCFR (the unofficial online Code of Federal Regulations) when we read them in October 2026. For the different rule that applies to cash received by a trade or business, see our guide to Form 8300 for accounting firms.

The reporting rule: 31 CFR 1010.311

Section 1010.311 requires each financial institution other than a casino to file a report of each deposit, withdrawal, exchange of currency or other payment or transfer, by, through or to the institution, which involves a transaction in currency of more than $10,000. The U.S. Postal Service is exempt for payments or transfers made solely to buy postage or philatelic products. The text on the eCFR shows no changes to this section after January 2017.

Aggregation: 31 CFR 1010.313

The threshold is not tested transaction by transaction. For institutions other than casinos, several currency transactions are treated as a single transaction if the institution knows they are by or on behalf of any person and they result in cash in or cash out totalling more than $10,000 during any one business day. Deposits made at night, over a weekend or on a holiday are treated as received on the next business day. The section also treats an institution as including all of its domestic branch offices, so activity at several branches counts toward one institution.

Identification before filing: 31 CFR 1010.312

Before completing a transaction that needs a currency report, the institution must verify and record the name and address of the individual presenting it, and the identity, account number and taxpayer identification number (if any) of any person on whose behalf it is conducted. For non-US residents, a passport, alien identification card or other official document showing nationality or residence can be used. For others, the institution examines a document that banks normally accept when cashing cheques for non-depositors, such as a driver's licence. The text bars entries such as "known customer" or "bank signature card on file".

Timing and retention: 31 CFR 1010.306

Reports under 1010.311 must be filed with FinCEN within 15 days following the day on which the reportable transaction occurred, and the institution must keep a copy for five years from the date of the report. Reports are filed on the prescribed forms, which for most reports come through the BSA E-Filing System.

Structuring: 31 CFR 1010.314

Section 1010.314 is addressed to "no person", so it is not limited to banks. It prohibits, for the purpose of evading the currency reporting requirements, causing or attempting to cause a domestic financial institution to fail to file a required report, causing or attempting to cause it to file a report with a material omission or misstatement, and structuring or assisting in structuring (or attempting to structure) a transaction with one or more domestic financial institutions. The purpose element matters: the section is aimed at conduct done to evade the reporting requirements.

How this connects to suspicious activity reporting

A currency transaction report is triggered by the amount and the facts, not by suspicion. Suspicious activity reporting is a separate duty. Our guide to the bank SAR rule explains how that rule works, and our overview of US AML requirements for CPAs shows where accounting firms sit in the picture.

Practical points for accountants: our suggestions

These are our suggestions, not requirements in the sections above. If a client tells you they plan to pay in or withdraw cash in smaller amounts "to stay under the limit", treat that as a conversation to have with your risk or compliance lead before you give any advice, because the stated aim is exactly what the structuring prohibition describes. Do not suggest ways of splitting cash payments. Keep a note of what the client said and what you advised. Make sure staff know the difference between a bank's currency transaction report, which the bank files, and Form 8300, which a business receiving cash may have to file.

What we could not confirm

We did not read the definition of "structure" in section 1010.100, the definition of currency, the exemption provisions for banks' customers, or the penalty provisions, so this post does not describe exemptions or sanctions. We did not look at FinCEN guidance on filing practice, or at any proposals to change the threshold, and we found no change to the sections above in the eCFR we read. The eCFR is unofficial, so anyone relying on the text should check the official Code of Federal Regulations. This post is general information, not legal advice.