I believe under the Patriot Act the magic number is $2500 now. That is why my bank questioned a transfer of more than $2500 between my accounts. Anything above $2500 is suspect. The post office has also been instructed to not forward any bank correspondence if you move and give them a forwarding address. If you don't notify your bank and they send something out in the interim, it is returned to the bank. I found this: Under the Bank Secrecy Act, banks and other financial institutions must report cash deposits greater than $10,000. But since many criminals are aware of that requirement, banks also are supposed to report any suspicious transactions, including deposit patterns below $10,000.Oct 25, 2014