31 C.F.R. § 1010.440
For the purposes of this chapter, a remittance or transfer of funds, or of currency, other monetary instruments, checks, investment securities, or credit to the domestic account of a person whose address is known by the person making the remittance or transfer, to be outside the United States, shall be deemed to be a remittance or transfer to a person outside the United States, except that, unless otherwise directed by the Secretary, this section shall not apply to a transaction on the books of a domestic financial institution involving the account of a customer of such institution whose address is within approximately 50 miles of the location of the institution, or who is known to be temporarily outside the United States.
31 C.F.R. §1010.440