The BSA only requires a CTR for currency transactions, including deposits, withdrawals, exchanges or transfers of currency over $10,000. A transaction in currency involves the physical transfer of currency from one person to another. Therefore, a transfer of currency below $10,000 would not require a CTR, despite the amount of the check.
FinCEN provides the following example as clarification for your question: If a person cashed a check for $10,100 and received $9,900 after a service fee was charged against the amount of the check, the financial institutions would not be required to file a CTR. If a person purchased a cashier’s check for $9,990 and paid a $20 service fee for a total of $10,010 in cash, the financial institution would be required to file a CTR. The key lies in the amount of the physical deposit, withdrawal, exchange or transfer of currency.