31 U.S.C. § 1323: Trust funds for certain fees, donations, quasi-public amounts, and unearned amounts

(a) Amounts from the following sources held in checking accounts of disbursing officials shall be deposited in the Treasury to the appropriate trust fund receipt accounts:(1) unearned money, lands (Department of the Interior). (2) reentry permit fees (Department of Justice). (3) naturalization fees (Department of Justice). (4) registry fees (Department of Justice). (b) Amounts deposited under subsection (a) of this section are appropriated for refunds. Earned parts of those amounts shall be transferred and credited to the appropriate receipt fund accounts. (c) Donations, quasi-public amounts, and unearned amounts shall be deposited in the Treasury as trust funds and are appropriated for disbursement under the terms of the trusts when the donation or amount is—(1) administered by officers and employees of the United States Government; and (2) carried in checking accounts of disbursing officials or others required to account to the Comptroller General (except clerks and marshals of the United States district courts).