California Code, Business and Professions Code - BPC § 22515

(a) “Money exchange house” means any individual or business engaged in the business of exchanging or dealing in the currency of the United States, Mexico, or any other country. It does not include any bank, savings association, or credit union chartered under the laws of this state or the United States or to any other business or entity regulated by the Financial Code.

(b) “Currency” means any coined money, banknotes, or other paper money as are authorized by law which circulates from hand to hand as the medium of exchange.

(c) “Buying dollars” means a transaction exchanging foreign currency for currency of the United States.

(d) “Selling dollars” means a transaction exchanging the currency of the United States for foreign currency.