Who Must File. Each financial institution (other than acasino, which instead must file FinCEN Form 103, and
the U.S. Postal Service for which there are separate rules)
must file FinCEN Form 104 (CTR) for each deposit,
withdrawal, exchange of currency, or other payment or
transfer, by, through, or to the financial institution which
involves a transaction in currency of more than $10,000.
Multiple transactions must be treated as a single
transaction if the financial institution has knowledge that
(1) they are by or on behalf of the same person, and (2)
they result in either currency received (Cash In) or currency
disbursed (Cash Out) by the financial institution totaling
more than $10,000 during any one business day.