31 U.S.C. § 5331: Reports relating to coins and currency received in nonfinancial trade or business

who is engaged in a trade or business, and who, in the course of such trade or business, receives more than $10,000 in coins or currency in 1 transaction (or 2 or more related transactions), or who is required to file a report under section 6050I(g) of the Internal Revenue Code of 1986, is in such form as the Secretary may prescribe; the name and address, and such other identification information as the Secretary may require, of the person from whom the coins or currency was received; the amount of coins or currency received; the date and nature of the transaction; and such other information, including the identification of the person filing the report, as the Secretary may prescribe. Subsection (a) shall not apply to amounts received in a transaction reported under section 5313 and regulations prescribed under such section. Except to the extent provided in regulations prescribed by the Secretary, subsection (a) shall not apply to any transaction if the entire transaction occurs outside the United States. foreign currency; and to the extent provided in regulations prescribed by the Secretary, any monetary instrument (whether or not in bearer form) with a face amount of not more than $10,000. Paragraph (1)(B) shall not apply to any check drawn on the account of the writer in a financial institution referred to in subparagraph (A), (B), (C), (D), (E), (F), (G), (J), (K), (R), or (S) of section 5312(a)(2).